diff --git a/browser_patches/firefox/BUILD_NUMBER b/browser_patches/firefox/BUILD_NUMBER
index bec4b5cd08..1f3d8a7a1f 100644
--- a/browser_patches/firefox/BUILD_NUMBER
+++ b/browser_patches/firefox/BUILD_NUMBER
@@ -1 +1 @@
-1025
+1028
diff --git a/browser_patches/firefox/archive.sh b/browser_patches/firefox/archive.sh
index e173a93721..1f652001b7 100755
--- a/browser_patches/firefox/archive.sh
+++ b/browser_patches/firefox/archive.sh
@@ -39,6 +39,7 @@ if [[ $OBJ_FOLDER == "" ]]; then
 fi
 
 ./mach package
+node ../install-preferences.js $PWD/$OBJ_FOLDER/dist/firefox
 
 if ! [[ -d $OBJ_FOLDER/dist/firefox ]]; then
   echo "ERROR: cannot find $OBJ_FOLDER/dist/firefox folder in the checkout/. Did you build?"
diff --git a/browser_patches/firefox/build.sh b/browser_patches/firefox/build.sh
index a2cd370054..fe8a8793a9 100755
--- a/browser_patches/firefox/build.sh
+++ b/browser_patches/firefox/build.sh
@@ -37,3 +37,11 @@ else
 fi
 
 ./mach build
+
+OBJ_FOLDER=$(ls -1 | grep obj-)
+if [[ "$(uname)" == "Darwin" ]]; then
+  node ../install-preferences.js $PWD/$OBJ_FOLDER/dist
+else
+  node ../install-preferences.js $PWD/$OBJ_FOLDER/dist/bin
+fi
+
diff --git a/browser_patches/firefox/install-preferences.js b/browser_patches/firefox/install-preferences.js
new file mode 100644
index 0000000000..f00f526392
--- /dev/null
+++ b/browser_patches/firefox/install-preferences.js
@@ -0,0 +1,96 @@
+/**
+ * Copyright 2018 Google Inc. All rights reserved.
+ * Modifications copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const os = require('os');
+const fs = require('fs');
+const path = require('path');
+const util = require('util');
+
+const writeFileAsync = util.promisify(fs.writeFile.bind(fs));
+const mkdirAsync = util.promisify(fs.mkdir.bind(fs));
+
+// Install browser preferences after downloading and unpacking
+// firefox instances.
+// Based on:   https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Enterprise_deployment_before_60#Configuration
+async function installFirefoxPreferences(distpath) {
+  let executablePath = '';
+  if (os.platform() === 'linux')
+    executablePath = path.join(distpath, 'firefox');
+  else if (os.platform() === 'darwin')
+    executablePath = path.join(distpath, 'Nightly.app', 'Contents', 'MacOS', 'firefox');
+  else if (os.platform() === 'win32')
+    executablePath = path.join(distpath, 'firefox.exe');
+
+  const firefoxFolder = path.dirname(executablePath);
+
+  let prefPath = '';
+  let configPath = '';
+  if (os.platform() === 'darwin') {
+    prefPath = path.join(firefoxFolder, '..', 'Resources', 'defaults', 'pref');
+    configPath = path.join(firefoxFolder, '..', 'Resources');
+  } else if (os.platform() === 'linux') {
+    if (!fs.existsSync(path.join(firefoxFolder, 'browser', 'defaults')))
+      await mkdirAsync(path.join(firefoxFolder, 'browser', 'defaults'));
+    if (!fs.existsSync(path.join(firefoxFolder, 'browser', 'defaults', 'preferences')))
+      await mkdirAsync(path.join(firefoxFolder, 'browser', 'defaults', 'preferences'));
+    prefPath = path.join(firefoxFolder, 'browser', 'defaults', 'preferences');
+    configPath = firefoxFolder;
+  } else if (os.platform() === 'win32') {
+    prefPath = path.join(firefoxFolder, 'defaults', 'pref');
+    configPath = firefoxFolder;
+  } else {
+    throw new Error('Unsupported platform: ' + os.platform());
+  }
+
+  await Promise.all([
+    copyFile({
+      from: path.join(__dirname, 'preferences', '00-playwright-prefs.js'),
+      to: path.join(prefPath, '00-playwright-prefs.js'),
+    }),
+    copyFile({
+      from: path.join(__dirname, 'preferences', 'playwright.cfg'),
+      to: path.join(configPath, 'playwright.cfg'),
+    }),
+  ]);
+}
+
+function copyFile({from, to}) {
+  const rd = fs.createReadStream(from);
+  const wr = fs.createWriteStream(to);
+  return new Promise(function(resolve, reject) {
+    rd.on('error', reject);
+    wr.on('error', reject);
+    wr.on('finish', resolve);
+    rd.pipe(wr);
+  }).catch(function(error) {
+    rd.destroy();
+    wr.end();
+    throw error;
+  });
+}
+
+if (process.argv.length !== 3) {
+  console.log('ERROR: expected a path to the directory with browser build');
+  process.exit(1);
+  return;
+}
+
+installFirefoxPreferences(process.argv[2]).catch(error => {
+  console.error('ERROR: failed to put preferences!');
+  console.error(error);
+  process.exit(1);
+});
diff --git a/browser_patches/firefox/patches/bootstrap.diff b/browser_patches/firefox/patches/bootstrap.diff
index ab1de60659..448fed1d00 100644
--- a/browser_patches/firefox/patches/bootstrap.diff
+++ b/browser_patches/firefox/patches/bootstrap.diff
@@ -469,10 +469,10 @@ index 6dca2b78830edc1ddbd66264bd332853729dac71..fbe89c9682834e11b9d9219d9eb056ed
  
 diff --git a/testing/juggler/BrowserContextManager.js b/testing/juggler/BrowserContextManager.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..a0a3799b6060692fa64f41411c0c276337d8f0c0
+index 0000000000000000000000000000000000000000..8f031b3f9afbb357a6bebc9938fca50a04d0421c
 --- /dev/null
 +++ b/testing/juggler/BrowserContextManager.js
-@@ -0,0 +1,174 @@
+@@ -0,0 +1,180 @@
 +"use strict";
 +
 +const {ContextualIdentityService} = ChromeUtils.import("resource://gre/modules/ContextualIdentityService.jsm");
@@ -503,9 +503,8 @@ index 0000000000000000000000000000000000000000..a0a3799b6060692fa64f41411c0c2763
 +  }
 +
 +  constructor() {
-+    this._browserContextIdToUserContextId = new Map();
-+    this._userContextIdToBrowserContextId = new Map();
-+    this._principalsForBrowserContextId = new Map();
++    this._browserContextIdToBrowserContext = new Map();
++    this._userContextIdToBrowserContext = new Map();
 +
 +    // Cleanup containers from previous runs (if any)
 +    for (const identity of ContextualIdentityService.getPublicIdentities()) {
@@ -514,66 +513,75 @@ index 0000000000000000000000000000000000000000..a0a3799b6060692fa64f41411c0c2763
 +        ContextualIdentityService.closeContainerTabs(identity.userContextId);
 +      }
 +    }
++
++    this._defaultContext = new BrowserContext(this, undefined, undefined);
 +  }
 +
-+  grantPermissions(browserContextId, origin, permissions) {
-+    const attrs = browserContextId ? {userContextId: this.userContextId(browserContextId)} : {};
++  createBrowserContext(options) {
++    return new BrowserContext(this, helper.generateId(), options);
++  }
++
++  browserContextForId(browserContextId) {
++    return this._browserContextIdToBrowserContext.get(browserContextId);
++  }
++
++  browserContextForUserContextId(userContextId) {
++    return this._userContextIdToBrowserContext.get(userContextId);
++  }
++
++  getBrowserContexts() {
++    return Array.from(this._browserContextIdToBrowserContext.values());
++  }
++}
++
++class BrowserContext {
++  constructor(manager, browserContextId, options) {
++    this._manager = manager;
++    this.browserContextId = browserContextId;
++    this.userContextId = undefined;
++    if (browserContextId !== undefined) {
++      const identity = ContextualIdentityService.create(IDENTITY_NAME + browserContextId);
++      this.userContextId = identity.userContextId;
++    }
++    this._principals = [];
++    this._manager._browserContextIdToBrowserContext.set(this.browserContextId, this);
++    this._manager._userContextIdToBrowserContext.set(this.userContextId, this);
++    this.options = options || {};
++  }
++
++  destroy() {
++    if (this.userContextId !== undefined) {
++      ContextualIdentityService.remove(this.userContextId);
++      ContextualIdentityService.closeContainerTabs(this.userContextId);
++    }
++    this._manager._browserContextIdToBrowserContext.delete(this.browserContextId);
++    this._manager._userContextIdToBrowserContext.delete(this.userContextId);
++  }
++
++  grantPermissions(origin, permissions) {
++    const attrs = {userContextId: this.userContextId};
 +    const principal = Services.scriptSecurityManager.createContentPrincipal(NetUtil.newURI(origin), attrs);
-+    if (!this._principalsForBrowserContextId.has(browserContextId))
-+      this._principalsForBrowserContextId.set(browserContextId, []);
-+    this._principalsForBrowserContextId.get(browserContextId).push(principal);
++    this._principals.push(principal);
 +    for (const permission of ALL_PERMISSIONS) {
 +      const action = permissions.includes(permission) ? Ci.nsIPermissionManager.ALLOW_ACTION : Ci.nsIPermissionManager.DENY_ACTION;
 +      Services.perms.addFromPrincipal(principal, permission, action);
 +    }
 +  }
 +
-+  resetPermissions(browserContextId) {
-+    if (!this._principalsForBrowserContextId.has(browserContextId))
-+      return;
-+    const principals = this._principalsForBrowserContextId.get(browserContextId);
-+    for (const principal of principals) {
++  resetPermissions() {
++    for (const principal of this._principals) {
 +      for (const permission of ALL_PERMISSIONS)
 +        Services.perms.removeFromPrincipal(principal, permission);
 +    }
-+    this._principalsForBrowserContextId.delete(browserContextId);
++    this._principals = [];
 +  }
 +
-+  createBrowserContext() {
-+    const browserContextId = helper.generateId();
-+    const identity = ContextualIdentityService.create(IDENTITY_NAME + browserContextId);
-+    this._browserContextIdToUserContextId.set(browserContextId, identity.userContextId);
-+    this._userContextIdToBrowserContextId.set(identity.userContextId, browserContextId);
-+    return browserContextId;
-+  }
-+
-+  browserContextId(userContextId) {
-+    return this._userContextIdToBrowserContextId.get(userContextId);
-+  }
-+
-+  userContextId(browserContextId) {
-+    return this._browserContextIdToUserContextId.get(browserContextId);
-+  }
-+
-+  removeBrowserContext(browserContextId) {
-+    const userContextId = this._browserContextIdToUserContextId.get(browserContextId);
-+    ContextualIdentityService.remove(userContextId);
-+    ContextualIdentityService.closeContainerTabs(userContextId);
-+    this._browserContextIdToUserContextId.delete(browserContextId);
-+    this._userContextIdToBrowserContextId.delete(userContextId);
-+  }
-+
-+  getBrowserContexts() {
-+    return Array.from(this._browserContextIdToUserContextId.keys());
-+  }
-+
-+  setCookies(browserContextId, cookies) {
++  setCookies(cookies) {
 +    const protocolToSameSite = {
 +      [undefined]: Ci.nsICookie.SAMESITE_NONE,
 +      'Lax': Ci.nsICookie.SAMESITE_LAX,
 +      'Strict': Ci.nsICookie.SAMESITE_STRICT,
 +    };
-+    const userContextId = browserContextId ? this._browserContextIdToUserContextId.get(browserContextId) : undefined;
 +    for (const cookie of cookies) {
 +      const uri = cookie.url ? NetUtil.newURI(cookie.url) : null;
 +      let domain = cookie.domain;
@@ -599,19 +607,17 @@ index 0000000000000000000000000000000000000000..a0a3799b6060692fa64f41411c0c2763
 +        cookie.httpOnly || false,
 +        cookie.expires === undefined || cookie.expires === -1 /* isSession */,
 +        cookie.expires === undefined ? Date.now() + HUNDRED_YEARS : cookie.expires,
-+        { userContextId } /* originAttributes */,
++        { userContextId: this.userContextId } /* originAttributes */,
 +        protocolToSameSite[cookie.sameSite],
 +      );
 +    }
 +  }
 +
-+  clearCookies(browserContextId) {
-+    const userContextId = browserContextId ? this._browserContextIdToUserContextId.get(browserContextId) : undefined;
-+    Services.cookies.removeCookiesWithOriginAttributes(JSON.stringify({ userContextId }));
++  clearCookies() {
++    Services.cookies.removeCookiesWithOriginAttributes(JSON.stringify({ userContextId: this.userContextId }));
 +  }
 +
-+  getCookies(browserContextId) {
-+    const userContextId = browserContextId ? this._browserContextIdToUserContextId.get(browserContextId) : 0;
++  getCookies() {
 +    const result = [];
 +    const sameSiteToProtocol = {
 +      [Ci.nsICookie.SAMESITE_NONE]: 'None',
@@ -619,7 +625,7 @@ index 0000000000000000000000000000000000000000..a0a3799b6060692fa64f41411c0c2763
 +      [Ci.nsICookie.SAMESITE_STRICT]: 'Strict',
 +    };
 +    for (let cookie of Services.cookies.cookies) {
-+      if (cookie.originAttributes.userContextId !== userContextId)
++      if (cookie.originAttributes.userContextId !== (this.userContextId || 0))
 +        continue;
 +      if (cookie.host === 'addons.mozilla.org')
 +        continue;
@@ -1444,10 +1450,10 @@ index 0000000000000000000000000000000000000000..66f61d432f9ad2f50931b780ec5ea0e3
 +this.NetworkObserver = NetworkObserver;
 diff --git a/testing/juggler/TargetRegistry.js b/testing/juggler/TargetRegistry.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..6231668027bb83bef2b3f839d44bcf043c5bb292
+index 0000000000000000000000000000000000000000..2b1a1bd0f931d82824a86ecbb46f86483177a4e0
 --- /dev/null
 +++ b/testing/juggler/TargetRegistry.js
-@@ -0,0 +1,196 @@
+@@ -0,0 +1,214 @@
 +const {EventEmitter} = ChromeUtils.import('resource://gre/modules/EventEmitter.jsm');
 +const {Helper} = ChromeUtils.import('chrome://juggler/content/Helper.js');
 +const {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
@@ -1481,9 +1487,14 @@ index 0000000000000000000000000000000000000000..6231668027bb83bef2b3f839d44bcf04
 +    this._tabToTarget = new Map();
 +
 +    for (const tab of this._mainWindow.gBrowser.tabs)
-+      this._ensureTargetForTab(tab);
++      this._createTargetForTab(tab);
 +    this._mainWindow.gBrowser.tabContainer.addEventListener('TabOpen', event => {
-+      this._ensureTargetForTab(event.target);
++      const target = this._createTargetForTab(event.target);
++      // If we come here, content will have juggler script from the start,
++      // and we should wait for initial navigation, unless the tab was window.open'ed.
++      target._waitForInitialNavigation = !event.target.linkedBrowser.hasContentOpener;
++      // For pages created before we attach to them, we don't wait for initial
++      // navigation (target._waitForInitialNavigation is false by default).
 +    });
 +    this._mainWindow.gBrowser.tabContainer.addEventListener('TabClose', event => {
 +      const tab = event.target;
@@ -1498,26 +1509,14 @@ index 0000000000000000000000000000000000000000..6231668027bb83bef2b3f839d44bcf04
 +  }
 +
 +  async newPage({browserContextId}) {
++    const browserContext = this._contextManager.browserContextForId(browserContextId);
 +    const tab = this._mainWindow.gBrowser.addTab('about:blank', {
-+      userContextId: this._contextManager.userContextId(browserContextId),
++      userContextId: browserContext.userContextId,
 +      triggeringPrincipal: Services.scriptSecurityManager.getSystemPrincipal(),
 +    });
 +    this._mainWindow.gBrowser.selectedTab = tab;
-+    // Await navigation to about:blank
-+    await new Promise(resolve => {
-+      const wpl = {
-+        onLocationChange: function(aWebProgress, aRequest, aLocation) {
-+          tab.linkedBrowser.removeProgressListener(wpl);
-+          resolve();
-+        },
-+        QueryInterface: ChromeUtils.generateQI([
-+          Ci.nsIWebProgressListener,
-+          Ci.nsISupportsWeakReference,
-+        ]),
-+      };
-+      tab.linkedBrowser.addProgressListener(wpl);
-+    });
-+    const target = this._ensureTargetForTab(tab);
++    const target = this._tabToTarget.get(tab);
++    await target._contentReadyPromise;
 +    return target.id();
 +  }
 +
@@ -1550,30 +1549,31 @@ index 0000000000000000000000000000000000000000..6231668027bb83bef2b3f839d44bcf04
 +    return target._tab;
 +  }
 +
-+  _ensureTargetForTab(tab) {
-+    if (this._tabToTarget.has(tab))
-+      return this._tabToTarget.get(tab);
-+    const openerTarget = tab.openerTab ? this._ensureTargetForTab(tab.openerTab) : null;
-+    const target = new PageTarget(this, tab, this._contextManager.browserContextId(tab.userContextId), openerTarget);
++  targetForId(targetId) {
++    return this._targets.get(targetId);
++  }
 +
++  _createTargetForTab(tab) {
++    if (this._tabToTarget.has(tab))
++      throw new Error(`Internal error: two targets per tab`);
++    const openerTarget = tab.openerTab ? this._tabToTarget.get(tab.openerTab) : null;
++    const target = new PageTarget(this, tab, this._contextManager.browserContextForUserContextId(tab.userContextId), openerTarget);
 +    this._targets.set(target.id(), target);
 +    this._tabToTarget.set(tab, target);
 +    this.emit(TargetRegistry.Events.TargetCreated, target.info());
++    return target;
 +  }
 +}
 +
 +class PageTarget {
-+  constructor(registry, tab, browserContextId, opener) {
++  constructor(registry, tab, browserContext, opener) {
 +    this._targetId = helper.generateId();
 +    this._registry = registry;
 +    this._tab = tab;
-+    this._browserContextId = browserContextId;
++    this._browserContext = browserContext;
 +    this._openerId = opener ? opener.id() : undefined;
 +    this._url = tab.linkedBrowser.currentURI.spec;
 +
-+    // First navigation always happens to about:blank - do not report it.
-+    this._skipNextNavigation = true;
-+
 +    const navigationListener = {
 +      QueryInterface: ChromeUtils.generateQI([ Ci.nsIWebProgressListener]),
 +      onLocationChange: (aWebProgress, aRequest, aLocation) => this._onNavigated(aLocation),
@@ -1584,13 +1584,41 @@ index 0000000000000000000000000000000000000000..6231668027bb83bef2b3f839d44bcf04
 +        receiveMessage: () => this._onContentReady()
 +      }),
 +    ];
++
++    this._contentReadyPromise = new Promise(f => this._contentReadyCallback = f);
++    this._waitForInitialNavigation = false;
++
++    if (browserContext && browserContext.options.viewport)
++      this.setViewportSize(browserContext.options.viewport.viewportSize);
++  }
++
++  setViewportSize(viewportSize) {
++    if (viewportSize) {
++      const {width, height} = viewportSize;
++      this._tab.linkedBrowser.style.setProperty('min-width', width + 'px');
++      this._tab.linkedBrowser.style.setProperty('min-height', height + 'px');
++      this._tab.linkedBrowser.style.setProperty('max-width', width + 'px');
++      this._tab.linkedBrowser.style.setProperty('max-height', height + 'px');
++    } else {
++      this._tab.linkedBrowser.style.removeProperty('min-width');
++      this._tab.linkedBrowser.style.removeProperty('min-height');
++      this._tab.linkedBrowser.style.removeProperty('max-width');
++      this._tab.linkedBrowser.style.removeProperty('max-height');
++    }
++    const rect = this._tab.linkedBrowser.getBoundingClientRect();
++    return { width: rect.width, height: rect.height };
 +  }
 +
 +  _onContentReady() {
-+    const attachInfo = [];
-+    const data = { attachInfo, targetInfo: this.info() };
++    const sessionIds = [];
++    const data = { sessionIds, targetInfo: this.info() };
 +    this._registry.emit(TargetRegistry.Events.PageTargetReady, data);
-+    return attachInfo;
++    this._contentReadyCallback();
++    return {
++      browserContextOptions: this._browserContext ? this._browserContext.options : {},
++      waitForInitialNavigation: this._waitForInitialNavigation,
++      sessionIds
++    };
 +  }
 +
 +  id() {
@@ -1602,16 +1630,12 @@ index 0000000000000000000000000000000000000000..6231668027bb83bef2b3f839d44bcf04
 +      targetId: this.id(),
 +      type: 'page',
 +      url: this._url,
-+      browserContextId: this._browserContextId,
++      browserContextId: this._browserContext ? this._browserContext.browserContextId : undefined,
 +      openerId: this._openerId,
 +    };
 +  }
 +
 +  _onNavigated(aLocation) {
-+    if (this._skipNextNavigation) {
-+      this._skipNextNavigation = false;
-+      return;
-+    }
 +    this._url = aLocation.spec;
 +    this._registry.emit(TargetRegistry.Events.TargetChanged, this.info());
 +  }
@@ -1792,10 +1816,10 @@ index 0000000000000000000000000000000000000000..268fbc361d8053182bb6c27f626e853d
 +
 diff --git a/testing/juggler/content/ContentSession.js b/testing/juggler/content/ContentSession.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..2302be180eeee0cc686171cefb56f7ab2514648a
+index 0000000000000000000000000000000000000000..3891da101e6906ae2a3888e256aefd03f724ab4b
 --- /dev/null
 +++ b/testing/juggler/content/ContentSession.js
-@@ -0,0 +1,67 @@
+@@ -0,0 +1,68 @@
 +const {Helper} = ChromeUtils.import('chrome://juggler/content/Helper.js');
 +const {RuntimeAgent} = ChromeUtils.import('chrome://juggler/content/content/RuntimeAgent.js');
 +const {PageAgent} = ChromeUtils.import('chrome://juggler/content/content/PageAgent.js');
@@ -1807,14 +1831,13 @@ index 0000000000000000000000000000000000000000..2302be180eeee0cc686171cefb56f7ab
 +   * @param {string} sessionId
 +   * @param {!ContentFrameMessageManager} messageManager
 +   * @param {!FrameTree} frameTree
-+   * @param {!ScrollbarManager} scrollbarManager
 +   * @param {!NetworkMonitor} networkMonitor
 +   */
-+  constructor(sessionId, messageManager, frameTree, scrollbarManager, networkMonitor) {
++  constructor(sessionId, messageManager, frameTree, networkMonitor) {
 +    this._sessionId = sessionId;
 +    this._messageManager = messageManager;
 +    const runtimeAgent = new RuntimeAgent(this);
-+    const pageAgent = new PageAgent(this, runtimeAgent, frameTree, scrollbarManager, networkMonitor);
++    const pageAgent = new PageAgent(this, runtimeAgent, frameTree, networkMonitor);
 +    this._agents = {
 +      Page: pageAgent,
 +      Runtime: runtimeAgent,
@@ -1822,6 +1845,8 @@ index 0000000000000000000000000000000000000000..2302be180eeee0cc686171cefb56f7ab
 +    this._eventListeners = [
 +      helper.addMessageListener(messageManager, this._sessionId, this._onMessage.bind(this)),
 +    ];
++    runtimeAgent.enable();
++    pageAgent.enable();
 +  }
 +
 +  emitEvent(eventName, params) {
@@ -1865,10 +1890,10 @@ index 0000000000000000000000000000000000000000..2302be180eeee0cc686171cefb56f7ab
 +
 diff --git a/testing/juggler/content/FrameTree.js b/testing/juggler/content/FrameTree.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..f239981ae0d87581d9a1c25ca1ebe1730d20bfa0
+index 0000000000000000000000000000000000000000..dcebb7bbf6d0c9bb7a350443dfa2574bee5915ea
 --- /dev/null
 +++ b/testing/juggler/content/FrameTree.js
-@@ -0,0 +1,242 @@
+@@ -0,0 +1,252 @@
 +"use strict";
 +const Ci = Components.interfaces;
 +const Cr = Components.results;
@@ -1880,10 +1905,11 @@ index 0000000000000000000000000000000000000000..f239981ae0d87581d9a1c25ca1ebe173
 +const helper = new Helper();
 +
 +class FrameTree {
-+  constructor(rootDocShell) {
++  constructor(rootDocShell, waitForInitialNavigation) {
 +    EventEmitter.decorate(this);
 +    this._docShellToFrame = new Map();
 +    this._frameIdToFrame = new Map();
++    this._pageReady = !waitForInitialNavigation;
 +    this._mainFrame = this._createFrame(rootDocShell);
 +    const webProgress = rootDocShell.QueryInterface(Ci.nsIInterfaceRequestor)
 +                                .getInterface(Ci.nsIWebProgress);
@@ -1902,6 +1928,10 @@ index 0000000000000000000000000000000000000000..f239981ae0d87581d9a1c25ca1ebe173
 +    ];
 +  }
 +
++  isPageReady() {
++    return this._pageReady;
++  }
++
 +  frameForDocShell(docShell) {
 +    return this._docShellToFrame.get(docShell) || null;
 +  }
@@ -1960,6 +1990,10 @@ index 0000000000000000000000000000000000000000..f239981ae0d87581d9a1c25ca1ebe173
 +      frame._lastCommittedNavigationId = navigationId;
 +      frame._url = channel.URI.spec;
 +      this.emit(FrameTree.Events.NavigationCommitted, frame);
++      if (frame === this._mainFrame && !this._pageReady) {
++        this._pageReady = true;
++        this.emit(FrameTree.Events.PageReady);
++      }
 +    } else if (isStop && frame._pendingNavigationId && status) {
 +      // Navigation is aborted.
 +      const navigationId = frame._pendingNavigationId;
@@ -2035,6 +2069,7 @@ index 0000000000000000000000000000000000000000..f239981ae0d87581d9a1c25ca1ebe173
 +  NavigationCommitted: 'navigationcommitted',
 +  NavigationAborted: 'navigationaborted',
 +  SameDocumentNavigation: 'samedocumentnavigation',
++  PageReady: 'pageready',
 +};
 +
 +class Frame {
@@ -2181,10 +2216,10 @@ index 0000000000000000000000000000000000000000..2508cce41565023b7fee9c7b85afe8ec
 +
 diff --git a/testing/juggler/content/PageAgent.js b/testing/juggler/content/PageAgent.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..d592ad9355e7e74a1685acd9338b387a8aa1b032
+index 0000000000000000000000000000000000000000..e505911e81ef014f19a3a732f3c5f631f0bd1780
 --- /dev/null
 +++ b/testing/juggler/content/PageAgent.js
-@@ -0,0 +1,895 @@
+@@ -0,0 +1,875 @@
 +"use strict";
 +const {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
 +const Ci = Components.interfaces;
@@ -2343,12 +2378,11 @@ index 0000000000000000000000000000000000000000..d592ad9355e7e74a1685acd9338b387a
 +}
 +
 +class PageAgent {
-+  constructor(session, runtimeAgent, frameTree, scrollbarManager, networkMonitor) {
++  constructor(session, runtimeAgent, frameTree, networkMonitor) {
 +    this._session = session;
 +    this._runtime = runtimeAgent;
 +    this._frameTree = frameTree;
 +    this._networkMonitor = networkMonitor;
-+    this._scrollbarManager = scrollbarManager;
 +
 +    this._frameData = new Map();
 +    this._scriptsToEvaluateOnNewDocument = new Map();
@@ -2399,14 +2433,6 @@ index 0000000000000000000000000000000000000000..d592ad9355e7e74a1685acd9338b387a
 +    return this._networkMonitor.requestDetails(channelId);
 +  }
 +
-+  async setViewport({deviceScaleFactor, isMobile, hasTouch}) {
-+    const docShell = this._frameTree.mainFrame().docShell();
-+    docShell.contentViewer.overrideDPPX = deviceScaleFactor || this._initialDPPX;
-+    docShell.deviceSizeIsPageSize = isMobile;
-+    docShell.touchEventsOverride = hasTouch ? Ci.nsIDocShell.TOUCHEVENTS_OVERRIDE_ENABLED : Ci.nsIDocShell.TOUCHEVENTS_OVERRIDE_NONE;
-+    this._scrollbarManager.setFloatingScrollbars(isMobile);
-+  }
-+
 +  async setEmulatedMedia({type, colorScheme}) {
 +    const docShell = this._frameTree.mainFrame().docShell();
 +    const cv = docShell.contentViewer;
@@ -2421,16 +2447,6 @@ index 0000000000000000000000000000000000000000..d592ad9355e7e74a1685acd9338b387a
 +    }
 +  }
 +
-+  async setUserAgent({userAgent}) {
-+    const docShell = this._frameTree.mainFrame().docShell();
-+    docShell.customUserAgent = userAgent;
-+  }
-+
-+  async setBypassCSP({enabled}) {
-+    const docShell = this._frameTree.mainFrame().docShell();
-+    docShell.bypassCSPEnabled = enabled;
-+  }
-+
 +  addScriptToEvaluateOnNewDocument({script, worldName}) {
 +    const scriptId = helper.generateId();
 +    this._scriptsToEvaluateOnNewDocument.set(scriptId, {script, worldName});
@@ -2454,11 +2470,6 @@ index 0000000000000000000000000000000000000000..d592ad9355e7e74a1685acd9338b387a
 +    docShell.defaultLoadFlags = cacheDisabled ? disable : enable;
 +  }
 +
-+  setJavascriptEnabled({enabled}) {
-+    const docShell = this._frameTree.mainFrame().docShell();
-+    docShell.allowJavascript = enabled;
-+  }
-+
 +  enable() {
 +    if (this._enabled)
 +      return;
@@ -2486,11 +2497,15 @@ index 0000000000000000000000000000000000000000..d592ad9355e7e74a1685acd9338b387a
 +      helper.on(this._frameTree, 'navigationcommitted', this._onNavigationCommitted.bind(this)),
 +      helper.on(this._frameTree, 'navigationaborted', this._onNavigationAborted.bind(this)),
 +      helper.on(this._frameTree, 'samedocumentnavigation', this._onSameDocumentNavigation.bind(this)),
++      helper.on(this._frameTree, 'pageready', () => this._session.emitEvent('Page.ready', {})),
 +    ];
 +
 +    this._wdm.addListener(this._wdmListener);
 +    for (const workerDebugger of this._wdm.getWorkerDebuggerEnumerator())
 +      this._onWorkerCreated(workerDebugger);
++
++    if (this._frameTree.isPageReady())
++      this._session.emitEvent('Page.ready', {});
 +  }
 +
 +  setInterceptFileChooserDialog({enabled}) {
@@ -3869,10 +3884,10 @@ index 0000000000000000000000000000000000000000..3a386425d3796d0a6786dea193b3402d
 +
 diff --git a/testing/juggler/content/main.js b/testing/juggler/content/main.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..6a9f908676fc025b74ea585a0e4e9194f704d13f
+index 0000000000000000000000000000000000000000..556f48d627401b8507b8bbec6dbf7ca797644baf
 --- /dev/null
 +++ b/testing/juggler/content/main.js
-@@ -0,0 +1,56 @@
+@@ -0,0 +1,76 @@
 +const {Helper} = ChromeUtils.import('chrome://juggler/content/Helper.js');
 +const {ContentSession} = ChromeUtils.import('chrome://juggler/content/content/ContentSession.js');
 +const {FrameTree} = ChromeUtils.import('chrome://juggler/content/content/FrameTree.js');
@@ -3880,17 +3895,15 @@ index 0000000000000000000000000000000000000000..6a9f908676fc025b74ea585a0e4e9194
 +const {ScrollbarManager} = ChromeUtils.import('chrome://juggler/content/content/ScrollbarManager.js');
 +
 +const sessions = new Map();
-+const frameTree = new FrameTree(docShell);
-+const networkMonitor = new NetworkMonitor(docShell, frameTree);
 +const scrollbarManager = new ScrollbarManager(docShell);
-+
++let frameTree;
++let networkMonitor;
 +const helper = new Helper();
 +const messageManager = this;
++let gListeners;
 +
 +function createContentSession(sessionId) {
-+  const session = new ContentSession(sessionId, messageManager, frameTree, scrollbarManager, networkMonitor);
-+  sessions.set(sessionId, session);
-+  return session;
++  sessions.set(sessionId, new ContentSession(sessionId, messageManager, frameTree, networkMonitor));
 +}
 +
 +function disposeContentSession(sessionId) {
@@ -3901,34 +3914,56 @@ index 0000000000000000000000000000000000000000..6a9f908676fc025b74ea585a0e4e9194
 +  session.dispose();
 +}
 +
-+const gListeners = [
-+  helper.addMessageListener(messageManager, 'juggler:create-content-session', msg => {
-+    const sessionId = msg.data;
++function initialize() {
++  let response = sendSyncMessage('juggler:content-ready', {})[0];
++  if (!response)
++    response = { sessionIds: [], browserContextOptions: {}, waitForInitialNavigation: false };
++
++  const { sessionIds, browserContextOptions, waitForInitialNavigation } = response;
++  const { userAgent, bypassCSP, javaScriptDisabled, viewport} = browserContextOptions;
++
++  if (userAgent !== undefined)
++    docShell.customUserAgent = userAgent;
++  if (bypassCSP !== undefined)
++    docShell.bypassCSPEnabled = bypassCSP;
++  if (javaScriptDisabled !== undefined)
++    docShell.allowJavascript = !javaScriptDisabled;
++  if (viewport !== undefined) {
++    docShell.contentViewer.overrideDPPX = viewport.deviceScaleFactor || this._initialDPPX;
++    docShell.deviceSizeIsPageSize = viewport.isMobile;
++    docShell.touchEventsOverride = viewport.hasTouch ? Ci.nsIDocShell.TOUCHEVENTS_OVERRIDE_ENABLED : Ci.nsIDocShell.TOUCHEVENTS_OVERRIDE_NONE;
++    scrollbarManager.setFloatingScrollbars(viewport.isMobile);
++  }
++
++  frameTree = new FrameTree(docShell, waitForInitialNavigation);
++  networkMonitor = new NetworkMonitor(docShell, frameTree);
++  for (const sessionId of sessionIds)
 +    createContentSession(sessionId);
-+  }),
 +
-+  helper.addMessageListener(messageManager, 'juggler:dispose-content-session', msg => {
-+    const sessionId = msg.data;
-+    disposeContentSession(sessionId);
-+  }),
++  gListeners = [
++    helper.addMessageListener(messageManager, 'juggler:create-content-session', msg => {
++      const sessionId = msg.data;
++      createContentSession(sessionId);
++    }),
 +
-+  helper.addEventListener(messageManager, 'unload', msg => {
-+    helper.removeListeners(gListeners);
-+    for (const session of sessions.values())
-+      session.dispose();
-+    sessions.clear();
-+    scrollbarManager.dispose();
-+    networkMonitor.dispose();
-+    frameTree.dispose();
-+  }),
-+];
++    helper.addMessageListener(messageManager, 'juggler:dispose-content-session', msg => {
++      const sessionId = msg.data;
++      disposeContentSession(sessionId);
++    }),
 +
-+const [attachInfo] = sendSyncMessage('juggler:content-ready', {});
-+for (const { sessionId, messages } of attachInfo || []) {
-+  const session = createContentSession(sessionId);
-+  for (const message of messages)
-+    session.handleMessage(message);
++    helper.addEventListener(messageManager, 'unload', msg => {
++      helper.removeListeners(gListeners);
++      for (const session of sessions.values())
++        session.dispose();
++      sessions.clear();
++      scrollbarManager.dispose();
++      networkMonitor.dispose();
++      frameTree.dispose();
++    }),
++  ];
 +}
++
++initialize();
 diff --git a/testing/juggler/jar.mn b/testing/juggler/jar.mn
 new file mode 100644
 index 0000000000000000000000000000000000000000..76377927a8c9af3cac3b028ff754491966d03ba3
@@ -4009,10 +4044,10 @@ index 0000000000000000000000000000000000000000..a2d3b79469566ca2edb7d864621f7085
 +this.AccessibilityHandler = AccessibilityHandler;
 diff --git a/testing/juggler/protocol/BrowserHandler.js b/testing/juggler/protocol/BrowserHandler.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..9bf14b3c4842d15508f67daa10f350475551a73e
+index 0000000000000000000000000000000000000000..6b42032e8f6d39025f455300d376084826a781cc
 --- /dev/null
 +++ b/testing/juggler/protocol/BrowserHandler.js
-@@ -0,0 +1,72 @@
+@@ -0,0 +1,73 @@
 +"use strict";
 +
 +const {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
@@ -4042,7 +4077,7 @@ index 0000000000000000000000000000000000000000..9bf14b3c4842d15508f67daa10f35047
 +
 +  async setIgnoreHTTPSErrors({enabled}) {
 +    if (!enabled) {
-+      allowAllCerts.disable() 
++      allowAllCerts.disable()
 +      Services.prefs.setBoolPref('security.mixed_content.block_active_content', true);
 +    } else {
 +      allowAllCerts.enable()
@@ -4051,23 +4086,24 @@ index 0000000000000000000000000000000000000000..9bf14b3c4842d15508f67daa10f35047
 +  }
 +
 +  grantPermissions({browserContextId, origin, permissions}) {
-+    this._contextManager.grantPermissions(browserContextId, origin, permissions);
++    this._contextManager.browserContextForId(browserContextId).grantPermissions(origin, permissions);
 +  }
 +
 +  resetPermissions({browserContextId}) {
-+    this._contextManager.resetPermissions(browserContextId);
++    this._contextManager.browserContextForId(browserContextId).resetPermissions();
 +  }
 +
 +  setCookies({browserContextId, cookies}) {
-+    this._contextManager.setCookies(browserContextId, cookies);
++    this._contextManager.browserContextForId(browserContextId).setCookies(cookies);
 +  }
 +
 +  clearCookies({browserContextId}) {
-+    this._contextManager.clearCookies(browserContextId);
++    this._contextManager.browserContextForId(browserContextId).clearCookies();
 +  }
 +
 +  getCookies({browserContextId}) {
-+    return {cookies: this._contextManager.getCookies(browserContextId)};
++    const cookies = this._contextManager.browserContextForId(browserContextId).getCookies();
++    return {cookies};
 +  }
 +
 +  async getInfo() {
@@ -4087,10 +4123,10 @@ index 0000000000000000000000000000000000000000..9bf14b3c4842d15508f67daa10f35047
 +this.BrowserHandler = BrowserHandler;
 diff --git a/testing/juggler/protocol/Dispatcher.js b/testing/juggler/protocol/Dispatcher.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..835aa8b7d1c5a8e643691c4b89da77cd1c8b18c9
+index 0000000000000000000000000000000000000000..5c5a73b35cd178b51899ab3dd681d46b6c3e4770
 --- /dev/null
 +++ b/testing/juggler/protocol/Dispatcher.js
-@@ -0,0 +1,254 @@
+@@ -0,0 +1,265 @@
 +const {TargetRegistry} = ChromeUtils.import("chrome://juggler/content/TargetRegistry.js");
 +const {protocol, checkScheme} = ChromeUtils.import("chrome://juggler/content/protocol/Protocol.js");
 +const {Helper} = ChromeUtils.import('chrome://juggler/content/Helper.js');
@@ -4123,7 +4159,7 @@ index 0000000000000000000000000000000000000000..835aa8b7d1c5a8e643691c4b89da77cd
 +    ];
 +  }
 +
-+  createSession(targetId) {
++  createSession(targetId, shouldConnect) {
 +    const targetInfo = TargetRegistry.instance().targetInfo(targetId);
 +    if (!targetInfo)
 +      throw new Error(`Target "${targetId}" is not found`);
@@ -4135,6 +4171,8 @@ index 0000000000000000000000000000000000000000..835aa8b7d1c5a8e643691c4b89da77cd
 +
 +    const sessionId = helper.generateId();
 +    const contentSession = targetInfo.type === 'page' ? new ContentSession(this, sessionId, targetInfo) : null;
++    if (shouldConnect && contentSession)
++      contentSession.connect();
 +    const chromeSession = new ChromeSession(this, sessionId, contentSession, targetInfo);
 +    targetSessions.set(sessionId, chromeSession);
 +    this._sessions.set(sessionId, chromeSession);
@@ -4234,6 +4272,12 @@ index 0000000000000000000000000000000000000000..835aa8b7d1c5a8e643691c4b89da77cd
 +      if (protocol.domains[domainName].targets.includes(targetInfo.type))
 +        this._handlers[domainName] = new handlerFactory(this, contentSession);
 +    }
++    const pageHandler = this._handlers['Page'];
++    if (pageHandler)
++      pageHandler.enable();
++    const networkHandler = this._handlers['Network'];
++    if (networkHandler)
++      networkHandler.enable();
 +  }
 +
 +  dispatcher() {
@@ -4284,7 +4328,6 @@ index 0000000000000000000000000000000000000000..835aa8b7d1c5a8e643691c4b89da77cd
 +    this._messageId = 0;
 +    this._pendingMessages = new Map();
 +    this._sessionId = sessionId;
-+    this._browser.messageManager.sendAsyncMessage('juggler:create-content-session', this._sessionId);
 +    this._disposed = false;
 +    this._eventListeners = [
 +      helper.addMessageListener(this._browser.messageManager, this._sessionId, {
@@ -4293,6 +4336,10 @@ index 0000000000000000000000000000000000000000..835aa8b7d1c5a8e643691c4b89da77cd
 +    ];
 +  }
 +
++  connect() {
++    this._browser.messageManager.sendAsyncMessage('juggler:create-content-session', this._sessionId);
++  }
++
 +  isDisposed() {
 +    return this._disposed;
 +  }
@@ -4519,10 +4566,10 @@ index 0000000000000000000000000000000000000000..5d776ab6f28ccff44ef4663e8618ad9c
 +this.NetworkHandler = NetworkHandler;
 diff --git a/testing/juggler/protocol/PageHandler.js b/testing/juggler/protocol/PageHandler.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..e9c5d94cf65b44d57bdb21ec892c3e325220a879
+index 0000000000000000000000000000000000000000..efb0fc1f3f7af37e101976cf8a682e09c223e59f
 --- /dev/null
 +++ b/testing/juggler/protocol/PageHandler.js
-@@ -0,0 +1,285 @@
+@@ -0,0 +1,266 @@
 +"use strict";
 +
 +const {Helper} = ChromeUtils.import('chrome://juggler/content/Helper.js');
@@ -4540,6 +4587,7 @@ index 0000000000000000000000000000000000000000..e9c5d94cf65b44d57bdb21ec892c3e32
 +  constructor(chromeSession, contentSession) {
 +    this._chromeSession = chromeSession;
 +    this._contentSession = contentSession;
++    this._pageTarget = TargetRegistry.instance().targetForId(chromeSession.targetId());
 +    this._browser = TargetRegistry.instance().tabForTarget(chromeSession.targetId()).linkedBrowser;
 +    this._dialogs = new Map();
 +
@@ -4568,38 +4616,18 @@ index 0000000000000000000000000000000000000000..e9c5d94cf65b44d57bdb21ec892c3e32
 +      }),
 +      helper.addEventListener(this._browser, 'DOMModalDialogClosed', event => this._updateModalDialogs()),
 +    ];
-+    await this._contentSession.send('Page.enable');
 +  }
 +
 +  dispose() {
 +    helper.removeListeners(this._eventListeners);
 +  }
 +
-+  async setViewport({viewport}) {
-+    if (viewport) {
-+      const {width, height} = viewport;
-+      this._browser.style.setProperty('min-width', width + 'px');
-+      this._browser.style.setProperty('min-height', height + 'px');
-+      this._browser.style.setProperty('max-width', width + 'px');
-+      this._browser.style.setProperty('max-height', height + 'px');
-+    } else {
-+      this._browser.style.removeProperty('min-width');
-+      this._browser.style.removeProperty('min-height');
-+      this._browser.style.removeProperty('max-width');
-+      this._browser.style.removeProperty('max-height');
-+    }
-+    const dimensions = this._browser.getBoundingClientRect();
-+    await Promise.all([
-+      this._contentSession.send('Page.setViewport', {
-+        deviceScaleFactor: viewport ? viewport.deviceScaleFactor : 0,
-+        isMobile: viewport && viewport.isMobile,
-+        hasTouch: viewport && viewport.hasTouch,
-+      }),
-+      this._contentSession.send('Page.awaitViewportDimensions', {
-+        width: dimensions.width,
-+        height: dimensions.height
-+      }),
-+    ]);
++  async setViewportSize({viewportSize}) {
++    const size = this._pageTarget.setViewportSize(viewportSize);
++    await this._contentSession.send('Page.awaitViewportDimensions', {
++      width: size.width,
++      height: size.height
++    });
 +  }
 +
 +  _updateModalDialogs() {
@@ -4959,10 +4987,10 @@ index 0000000000000000000000000000000000000000..78b6601b91d0b7fcda61114e6846aa07
 +this.EXPORTED_SYMBOLS = ['t', 'checkScheme'];
 diff --git a/testing/juggler/protocol/Protocol.js b/testing/juggler/protocol/Protocol.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497a16559ea
+index 0000000000000000000000000000000000000000..a0a96a87ff4a422deccae1045962690fa7941f25
 --- /dev/null
 +++ b/testing/juggler/protocol/Protocol.js
-@@ -0,0 +1,755 @@
+@@ -0,0 +1,746 @@
 +const {t, checkScheme} = ChromeUtils.import('chrome://juggler/content/protocol/PrimitiveTypes.js');
 +
 +// Protocol-specific types.
@@ -5016,13 +5044,16 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +  height: t.Number,
 +};
 +
-+pageTypes.Viewport = {
++pageTypes.Size = {
 +  width: t.Number,
 +  height: t.Number,
++};
++
++pageTypes.Viewport = {
++  viewportSize: pageTypes.Size,
 +  deviceScaleFactor: t.Number,
 +  isMobile: t.Boolean,
 +  hasTouch: t.Boolean,
-+  isLandscape: t.Boolean,
 +};
 +
 +pageTypes.DOMQuad = {
@@ -5218,6 +5249,9 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +      params: {
 +        removeOnDetach: t.Optional(t.Boolean),
 +        userAgent: t.Optional(t.String),
++        bypassCSP: t.Optional(t.Boolean),
++        javaScriptDisabled: t.Optional(t.Boolean),
++        viewport: t.Optional(pageTypes.Viewport),
 +      },
 +      returns: {
 +        browserContextId: t.String,
@@ -5288,7 +5322,6 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +    },
 +  },
 +  methods: {
-+    'enable': {},
 +    'setRequestInterception': {
 +      params: {
 +        enabled: t.Boolean,
@@ -5359,9 +5392,6 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +    },
 +  },
 +  methods: {
-+    'enable': {
-+      params: {},
-+    },
 +    'evaluate': {
 +      params: {
 +        // Pass frameId here.
@@ -5414,6 +5444,8 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +
 +  types: pageTypes,
 +  events: {
++    'ready': {
++    },
 +    'eventFired': {
 +      frameId: t.String,
 +      name: t.Enum(['load', 'DOMContentLoaded']),
@@ -5485,9 +5517,6 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +  },
 +
 +  methods: {
-+    'enable': {
-+      params: {},
-+    },
 +    'close': {
 +      params: {
 +        runBeforeUnload: t.Optional(t.Boolean),
@@ -5505,9 +5534,9 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +        name: t.String,
 +      },
 +    },
-+    'setViewport': {
++    'setViewportSize': {
 +      params: {
-+        viewport: t.Nullable(pageTypes.Viewport),
++        viewportSize: t.Nullable(pageTypes.Size),
 +      },
 +    },
 +    'setEmulatedMedia': {
@@ -5516,21 +5545,11 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +        colorScheme: t.Optional(t.Enum(['dark', 'light', 'no-preference'])),
 +      },
 +    },
-+    'setBypassCSP': {
-+      params: {
-+        enabled: t.Boolean
-+      }
-+    },
 +    'setCacheDisabled': {
 +      params: {
 +        cacheDisabled: t.Boolean,
 +      },
 +    },
-+    'setJavascriptEnabled': {
-+      params: {
-+        enabled: t.Boolean,
-+      },
-+    },
 +    'describeNode': {
 +      params: {
 +        frameId: t.String,
@@ -5720,10 +5739,10 @@ index 0000000000000000000000000000000000000000..a59a7c218fdc3d2b3282bc5419eb4497
 +this.EXPORTED_SYMBOLS = ['protocol', 'checkScheme'];
 diff --git a/testing/juggler/protocol/RuntimeHandler.js b/testing/juggler/protocol/RuntimeHandler.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..0026e8ff58ef6268f4c63783d0ff68ff355b1e72
+index 0000000000000000000000000000000000000000..089e66c617f114fcb32b3cea20abc6fb80e26a1e
 --- /dev/null
 +++ b/testing/juggler/protocol/RuntimeHandler.js
-@@ -0,0 +1,41 @@
+@@ -0,0 +1,37 @@
 +"use strict";
 +
 +const {Helper} = ChromeUtils.import('chrome://juggler/content/Helper.js');
@@ -5740,10 +5759,6 @@ index 0000000000000000000000000000000000000000..0026e8ff58ef6268f4c63783d0ff68ff
 +    this._contentSession = contentSession;
 +  }
 +
-+  async enable(options) {
-+    return await this._contentSession.send('Runtime.enable', options);
-+  }
-+
 +  async evaluate(options) {
 +    return await this._contentSession.send('Runtime.evaluate', options);
 +  }
@@ -5767,10 +5782,10 @@ index 0000000000000000000000000000000000000000..0026e8ff58ef6268f4c63783d0ff68ff
 +this.RuntimeHandler = RuntimeHandler;
 diff --git a/testing/juggler/protocol/TargetHandler.js b/testing/juggler/protocol/TargetHandler.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..454fa4ebb9bda29bb957fa64a08ca92c33212f75
+index 0000000000000000000000000000000000000000..4795a4ddecdd016d6efbcde35aa7321af17cd7dc
 --- /dev/null
 +++ b/testing/juggler/protocol/TargetHandler.js
-@@ -0,0 +1,104 @@
+@@ -0,0 +1,100 @@
 +"use strict";
 +
 +const {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
@@ -5789,34 +5804,34 @@ index 0000000000000000000000000000000000000000..454fa4ebb9bda29bb957fa64a08ca92c
 +    this._targetRegistry = TargetRegistry.instance();
 +    this._enabled = false;
 +    this._eventListeners = [];
-+    this._createdBrowserContextOptions = new Map();
++    this._createdBrowserContextIds = new Set();
 +  }
 +
 +  async attachToTarget({targetId}) {
 +    if (!this._enabled)
 +      throw new Error('Target domain is not enabled');
-+    const sessionId = this._session.dispatcher().createSession(targetId);
++    const sessionId = this._session.dispatcher().createSession(targetId, true /* shouldConnect */);
 +    return {sessionId};
 +  }
 +
 +  async createBrowserContext(options) {
 +    if (!this._enabled)
 +      throw new Error('Target domain is not enabled');
-+    const browserContextId = this._contextManager.createBrowserContext();
-+    // TODO: introduce BrowserContext class, with options?
-+    this._createdBrowserContextOptions.set(browserContextId, options);
-+    return {browserContextId};
++    const browserContext = this._contextManager.createBrowserContext(options);
++    this._createdBrowserContextIds.add(browserContext.browserContextId);
++    return {browserContextId: browserContext.browserContextId};
 +  }
 +
 +  async removeBrowserContext({browserContextId}) {
 +    if (!this._enabled)
 +      throw new Error('Target domain is not enabled');
-+    this._createdBrowserContextOptions.delete(browserContextId);
-+    this._contextManager.removeBrowserContext(browserContextId);
++    this._createdBrowserContextIds.delete(browserContextId);
++    this._contextManager.browserContextForId(browserContextId).destroy();
 +  }
 +
 +  async getBrowserContexts() {
-+    return {browserContextIds: this._contextManager.getBrowserContexts()};
++    const browserContexts = this._contextManager.getBrowserContexts();
++    return {browserContextIds: browserContexts.map(bc => bc.browserContextId)};
 +  }
 +
 +  async enable() {
@@ -5836,9 +5851,10 @@ index 0000000000000000000000000000000000000000..454fa4ebb9bda29bb957fa64a08ca92c
 +
 +  dispose() {
 +    helper.removeListeners(this._eventListeners);
-+    for (const [browserContextId, options] of this._createdBrowserContextOptions) {
-+      if (options.removeOnDetach)
-+        this._contextManager.removeBrowserContext(browserContextId);
++    for (const browserContextId of this._createdBrowserContextIds) {
++      const browserContext = this._contextManager.browserContextForId(browserContextId);
++      if (browserContext.options.removeOnDetach)
++        browserContext.destroy();
 +    }
 +    this._createdBrowserContextOptions.clear();
 +  }
@@ -5855,16 +5871,11 @@ index 0000000000000000000000000000000000000000..454fa4ebb9bda29bb957fa64a08ca92c
 +    this._session.emitEvent('Target.targetDestroyed', targetInfo);
 +  }
 +
-+  _onPageTargetReady({attachInfo, targetInfo}) {
-+    const options = this._createdBrowserContextOptions.get(targetInfo.browserContextId);
-+    if (!options)
++  _onPageTargetReady({sessionIds, targetInfo}) {
++    if (!this._createdBrowserContextIds.has(targetInfo.browserContextId))
 +      return;
-+    const sessionId = this._session.dispatcher().createSession(targetInfo.targetId);
-+    const messages = [];
-+    // TODO: perhaps, we should just have a single message 'initBrowserContextOptions'.
-+    if (options.userAgent !== undefined)
-+      messages.push({ id: 0, methodName: 'Page.setUserAgent', params: { userAgent: options.userAgent } });
-+    attachInfo.push({ sessionId, messages });
++    const sessionId = this._session.dispatcher().createSession(targetInfo.targetId, false /* shouldConnect */);
++    sessionIds.push(sessionId);
 +  }
 +
 +  async newPage({browserContextId}) {
diff --git a/browser_patches/firefox/preferences/00-playwright-prefs.js b/browser_patches/firefox/preferences/00-playwright-prefs.js
new file mode 100644
index 0000000000..1895d2d1b7
--- /dev/null
+++ b/browser_patches/firefox/preferences/00-playwright-prefs.js
@@ -0,0 +1,3 @@
+// Any comment. You must start the file with a single-line comment!
+pref("general.config.filename", "playwright.cfg");
+pref("general.config.obscure_value", 0);
diff --git a/browser_patches/firefox/preferences/playwright.cfg b/browser_patches/firefox/preferences/playwright.cfg
new file mode 100644
index 0000000000..4e724051fd
--- /dev/null
+++ b/browser_patches/firefox/preferences/playwright.cfg
@@ -0,0 +1,233 @@
+// Any comment. You must start the file with a comment!
+
+// Make sure Shield doesn't hit the network.
+pref("app.normandy.api_url", "");
+pref("app.normandy.enabled", false);
+
+// Disable updater
+pref("app.update.enabled", false);
+// Disable Firefox old build background check
+pref("app.update.checkInstallTime", false);
+// Disable automatically upgrading Firefox
+pref("app.update.disabledForTesting", true);
+
+// make absolutely sure it is really off
+pref("app.update.auto", false);
+pref("app.update.mode", 0);
+pref("app.update.service.enabled", false);
+// Dislabe newtabpage
+pref("browser.startup.homepage", "about:blank");
+pref("browser.startup.page", 0);
+pref("browser.newtabpage.enabled", false);
+// Do not redirect user when a milstone upgrade of Firefox is detected
+pref("browser.startup.homepage_override.mstone", "ignore");
+
+// Disable topstories
+pref("browser.newtabpage.activity-stream.feeds.section.topstories", false);
+// DevTools JSONViewer sometimes fails to load dependencies with its require.js.
+// This doesn't affect Puppeteer operations, but spams console with a lot of
+// unpleasant errors.
+// (bug 1424372)
+pref("devtools.jsonview.enabled", false);
+
+// Prevent various error message on the console
+pref("browser.contentblocking.features.standard", "-tp,tpPrivate,cookieBehavior0,-cm,-fp");
+pref("network.cookie.cookieBehavior", 0);
+
+// Increase the APZ content response timeout in tests to 1 minute.
+// This is to accommodate the fact that test environments tends to be
+// slower than production environments (with the b2g emulator being
+// the slowest of them all), resulting in the production timeout value
+// sometimes being exceeded and causing false-positive test failures.
+//
+// (bug 1176798, bug 1177018, bug 1210465)
+pref("apz.content_response_timeout", 60000);
+
+// Allow creating files in content process - required for
+// |Page.setFileInputFiles| protocol method.
+pref("dom.file.createInChild", true);
+
+// Indicate that the download panel has been shown once so that
+// whichever download test runs first doesn't show the popup
+// inconsistently.
+pref("browser.download.panel.shown", true);
+// Background thumbnails in particular cause grief, and disabling
+// thumbnails in general cannot hurt
+pref("browser.pagethumbnails.capturing_disabled", true);
+// Disable safebrowsing components.
+pref("browser.safebrowsing.blockedURIs.enabled", false);
+pref("browser.safebrowsing.downloads.enabled", false);
+pref("browser.safebrowsing.passwords.enabled", false);
+pref("browser.safebrowsing.malware.enabled", false);
+pref("browser.safebrowsing.phishing.enabled", false);
+// Disable updates to search engines.
+pref("browser.search.update", false);
+// Do not restore the last open set of tabs if the browser has crashed
+pref("browser.sessionstore.resume_from_crash", false);
+// Don't check for the default web browser during startup.
+pref("browser.shell.checkDefaultBrowser", false);
+
+// Disable browser animations (tabs, fullscreen, sliding alerts)
+pref("toolkit.cosmeticAnimations.enabled", false);
+
+// Close the window when the last tab gets closed
+pref("browser.tabs.closeWindowWithLastTab", true);
+
+// Do not allow background tabs to be zombified on Android, otherwise for
+// tests that open additional tabs, the test harness tab itself might get
+// unloaded
+pref("browser.tabs.disableBackgroundZombification", false);
+
+// Do not warn when closing all open tabs
+pref("browser.tabs.warnOnClose", false);
+
+// Do not warn when closing all other open tabs
+pref("browser.tabs.warnOnCloseOtherTabs", false);
+
+// Do not warn when multiple tabs will be opened
+pref("browser.tabs.warnOnOpen", false);
+
+// Disable first run splash page on Windows 10
+pref("browser.usedOnWindows10.introURL", "");
+
+// Disable the UI tour.
+//
+// Should be set in profile.
+pref("browser.uitour.enabled", false);
+
+// Turn off search suggestions in the location bar so as not to trigger
+// network connections.
+pref("browser.urlbar.suggest.searches", false);
+
+// Do not warn on quitting Firefox
+pref("browser.warnOnQuit", false);
+
+// Do not show datareporting policy notifications which can
+// interfere with tests
+pref("datareporting.healthreport.documentServerURI", "http://dummydummy.test/dummy/healthreport/");
+pref("datareporting.healthreport.about.reportUrl", "http://dummydummy.test/dummy/abouthealthreport/");
+pref("datareporting.healthreport.logging.consoleEnabled", false);
+pref("datareporting.healthreport.service.enabled", false);
+pref("datareporting.healthreport.service.firstRun", false);
+pref("datareporting.healthreport.uploadEnabled", false);
+pref("datareporting.policy.dataSubmissionEnabled", false);
+pref("datareporting.policy.dataSubmissionPolicyAccepted", false);
+pref("datareporting.policy.dataSubmissionPolicyBypassNotification", true);
+
+// Automatically unload beforeunload alerts
+pref("dom.disable_beforeunload", false);
+
+// Disable popup-blocker
+pref("dom.disable_open_during_load", false);
+
+// Disable the ProcessHangMonitor
+pref("dom.ipc.reportProcessHangs", false);
+pref("hangmonitor.timeout", 0);
+
+// Disable slow script dialogues
+pref("dom.max_chrome_script_run_time", 0);
+pref("dom.max_script_run_time", 0);
+
+// Only load extensions from the application and user profile
+// AddonManager.SCOPE_PROFILE + AddonManager.SCOPE_APPLICATION
+pref("extensions.autoDisableScopes", 0);
+pref("extensions.enabledScopes", 5);
+
+// Disable metadata caching for installed add-ons by default
+pref("extensions.getAddons.cache.enabled", false);
+
+// Disable installing any distribution extensions or add-ons.
+pref("extensions.installDistroAddons", false);
+
+// Turn off extension updates so they do not bother tests
+pref("extensions.update.enabled", false);
+pref("extensions.update.notifyUser", false);
+
+// Make sure opening about:addons will not hit the network
+pref("extensions.webservice.discoverURL", "http://dummydummy.test/dummy/discoveryURL");
+
+pref("extensions.screenshots.disabled", true);
+pref("extensions.screenshots.upload-disabled", true);
+
+// Allow the application to have focus even it runs in the background
+pref("focusmanager.testmode", true);
+
+// Disable useragent updates
+pref("general.useragent.updates.enabled", false);
+
+// No ICC color correction.
+// See https://developer.mozilla.org/en/docs/Mozilla/Firefox/Releases/3.5/ICC_color_correction_in_Firefox.
+pref("gfx.color_management.mode", 0);
+pref("gfx.color_management.rendering_intent", 3);
+
+// Always use network provider for geolocation tests so we bypass the
+// macOS dialog raised by the corelocation provider
+pref("geo.provider.testing", true);
+
+// Do not scan Wifi
+pref("geo.wifi.scan", false);
+
+// Show chrome errors and warnings in the error console
+pref("javascript.options.showInConsole", true);
+
+// Disable download and usage of OpenH264: and Widevine plugins
+pref("media.gmp-manager.updateEnabled", false);
+
+// Do not prompt with long usernames or passwords in URLs
+pref("network.http.phishy-userpass-length", 255);
+
+// Do not prompt for temporary redirects
+pref("network.http.prompt-temp-redirect", false);
+
+// Disable speculative connections so they are not reported as leaking
+// when they are hanging around
+pref("network.http.speculative-parallel-limit", 0);
+
+// Do not automatically switch between offline and online
+pref("network.manage-offline-status", false);
+
+// Make sure SNTP requests do not hit the network
+pref("network.sntp.pools", "dummydummy.test");
+
+// Disable Flash
+pref("plugin.state.flash", 0);
+
+pref("privacy.trackingprotection.enabled", false);
+
+pref("security.certerrors.mitm.priming.enabled", false);
+
+// Local documents have access to all other local documents,
+// including directory listings
+pref("security.fileuri.strict_origin_policy", false);
+
+// Tests do not wait for the notification button security delay
+pref("security.notification_enable_delay", 0);
+
+// Ensure blocklist updates do not hit the network
+pref("services.settings.server", "http://dummydummy.test/dummy/blocklist/");
+
+// Disable DocumentChannel.
+// See https://github.com/microsoft/playwright/pull/451
+pref("browser.tabs.documentchannel", false);
+
+// Do not automatically fill sign-in forms with known usernames and
+// passwords
+pref("signon.autofillForms", false);
+
+// Disable password capture, so that tests that include forms are not
+// influenced by the presence of the persistent doorhanger notification
+pref("signon.rememberSignons", false);
+
+// Disable first-run welcome page
+pref("startup.homepage_welcome_url", "about:blank");
+pref("startup.homepage_welcome_url.additional", "");
+
+// Prevent starting into safe mode after application crashes
+pref("toolkit.startup.max_resumed_crashes", -1);
+lockPref("toolkit.crashreporter.enabled", false);
+
+pref("toolkit.telemetry.enabled", false);
+pref("toolkit.telemetry.server", "https://dummydummy.test/dummy/telemetry");
+
+// Disable crash reporter.
+Components.classes["@mozilla.org/toolkit/crash-reporter;1"].getService(Components.interfaces.nsICrashReporter).submitReports = false;
diff --git a/browser_patches/webkit/BUILD_NUMBER b/browser_patches/webkit/BUILD_NUMBER
index e60c25e12e..e29bf83e37 100644
--- a/browser_patches/webkit/BUILD_NUMBER
+++ b/browser_patches/webkit/BUILD_NUMBER
@@ -1 +1 @@
-1141
+1143
diff --git a/browser_patches/webkit/patches/bootstrap.diff b/browser_patches/webkit/patches/bootstrap.diff
index 2457a295bc..010770f8c5 100644
--- a/browser_patches/webkit/patches/bootstrap.diff
+++ b/browser_patches/webkit/patches/bootstrap.diff
@@ -731,10 +731,10 @@ index 0000000000000000000000000000000000000000..79edea03fed4e9be5da96e1275e182a4
 +}
 diff --git a/Source/JavaScriptCore/inspector/protocol/Emulation.json b/Source/JavaScriptCore/inspector/protocol/Emulation.json
 new file mode 100644
-index 0000000000000000000000000000000000000000..bcf863e4bba3b99f66e75dabfc4d8c1289cc2b78
+index 0000000000000000000000000000000000000000..552e5dd60fa53fada79f8d6e333f52bc10a2bead
 --- /dev/null
 +++ b/Source/JavaScriptCore/inspector/protocol/Emulation.json
-@@ -0,0 +1,32 @@
+@@ -0,0 +1,39 @@
 +{
 +    "domain": "Emulation",
 +    "availability": ["web"],
@@ -764,6 +764,13 @@ index 0000000000000000000000000000000000000000..bcf863e4bba3b99f66e75dabfc4d8c12
 +                { "name": "username", "type": "string", "optional": true },
 +                { "name": "password", "type": "string", "optional": true }
 +            ]
++        },
++        {
++            "name": "setActiveAndFocused",
++            "description": "Makes page focused for test.",
++            "parameters": [
++                { "name": "active", "type": "boolean", "optional": true }
++            ]
 +        }
 +    ]
 +}
@@ -8723,10 +8730,10 @@ index 846a5aa27dfab3d274cffa4873861f2587d17fd8..cf0dc99f5601636c48abff09cd47ace4
  
 diff --git a/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.cpp b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.cpp
 new file mode 100644
-index 0000000000000000000000000000000000000000..78815bc17978a23ca811ff99039b4fe86e6fb4a0
+index 0000000000000000000000000000000000000000..466d5129363e8b3d2e7cfc10f2a1ac7ae77f634f
 --- /dev/null
 +++ b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.cpp
-@@ -0,0 +1,95 @@
+@@ -0,0 +1,103 @@
 +/*
 + * Copyright (C) 2019 Microsoft Corporation.
 + *
@@ -8821,13 +8828,21 @@ index 0000000000000000000000000000000000000000..78815bc17978a23ca811ff99039b4fe8
 +        m_page.setAuthCredentialsForAutomation(Optional<WebCore::Credential>());
 +}
 +
++void WebPageInspectorEmulationAgent::setActiveAndFocused(Inspector::ErrorString&, const bool* active)
++{
++    Optional<bool> value;
++    if (active)
++      value = *active;
++    m_page.setActiveForAutomation(value);
++}
++
 +} // namespace WebKit
 diff --git a/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.h b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.h
 new file mode 100644
-index 0000000000000000000000000000000000000000..77dff2c191fee081773bc5705d80168c3898f496
+index 0000000000000000000000000000000000000000..43d827233df725fa8c85fc9ff4b20a1f716803e0
 --- /dev/null
 +++ b/Source/WebKit/UIProcess/WebPageInspectorEmulationAgent.h
-@@ -0,0 +1,66 @@
+@@ -0,0 +1,67 @@
 +/*
 + * Copyright (C) 2019 Microsoft Corporation.
 + *
@@ -8885,6 +8900,7 @@ index 0000000000000000000000000000000000000000..77dff2c191fee081773bc5705d80168c
 +    void setDeviceMetricsOverride(int width, int height, double deviceScaleFactor, bool fixedlayout, Ref<SetDeviceMetricsOverrideCallback>&&) override;
 +    void setJavaScriptEnabled(Inspector::ErrorString&, bool enabled) override;
 +    void setAuthCredentials(Inspector::ErrorString&, const String*, const String*) override;
++    void setActiveAndFocused(Inspector::ErrorString&, const bool*) override;
 +
 +private:
 +    void platformSetSize(int width, int height, Function<void (const String& error)>&&);
@@ -9235,7 +9251,7 @@ index 0000000000000000000000000000000000000000..76290475097e756e3d932d22be4d8c79
 +
 +} // namespace WebKit
 diff --git a/Source/WebKit/UIProcess/WebPageProxy.cpp b/Source/WebKit/UIProcess/WebPageProxy.cpp
-index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e7772056b250ee5 100644
+index 059e904a16c6c4b91d6271e25d239b975191facd..df51560a3abc953030e7cb7602275c0a9ab72281 100644
 --- a/Source/WebKit/UIProcess/WebPageProxy.cpp
 +++ b/Source/WebKit/UIProcess/WebPageProxy.cpp
 @@ -905,6 +905,7 @@ void WebPageProxy::finishAttachingToWebProcess(ProcessLaunchReason reason)
@@ -9268,18 +9284,30 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
  RefPtr<API::Navigation> WebPageProxy::loadRequest(ResourceRequest&& request, ShouldOpenExternalURLsPolicy shouldOpenExternalURLsPolicy, API::Object* userData)
  {
      if (m_isClosed)
-@@ -1680,6 +1696,19 @@ void WebPageProxy::setControlledByAutomation(bool controlled)
+@@ -1680,6 +1696,31 @@ void WebPageProxy::setControlledByAutomation(bool controlled)
      m_process->processPool().sendToNetworkingProcess(Messages::NetworkProcess::SetSessionIsControlledByAutomation(m_websiteDataStore->sessionID(), m_controlledByAutomation));
  }
  
-+void WebPageProxy::setAuthCredentialsForAutomation(Optional<WebCore::Credential>&& credentials) {
++void WebPageProxy::setAuthCredentialsForAutomation(Optional<WebCore::Credential>&& credentials)
++{
 +    m_credentialsForAutomation = WTFMove(credentials);
 +}
 +
-+void WebPageProxy::setPermissionsForAutomation(const HashMap<String, HashSet<String>>& permissions) {
++void WebPageProxy::setPermissionsForAutomation(const HashMap<String, HashSet<String>>& permissions)
++{
 +    m_permissionsForAutomation = permissions;
 +}
 +
++void WebPageProxy::setActiveForAutomation(Optional<bool> active) {
++    m_activeForAutomation = active;
++    OptionSet<ActivityState::Flag> state;
++    state.add(ActivityState::IsFocused);
++    state.add(ActivityState::WindowIsActive);
++    state.add(ActivityState::IsVisible);
++    state.add(ActivityState::IsVisibleOrOccluded);
++    activityStateDidChange(state);
++}
++
 +void WebPageProxy::logToStderr(const String& str)
 +{
 +    fprintf(stderr, "RENDERER: %s\n", str.utf8().data());
@@ -9288,7 +9316,33 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
  void WebPageProxy::createInspectorTarget(const String& targetId, Inspector::InspectorTargetType type)
  {
      MESSAGE_CHECK(m_process, !targetId.isEmpty());
-@@ -2767,7 +2796,7 @@ static TrackingType mergeTrackingTypes(TrackingType a, TrackingType b)
+@@ -1822,6 +1863,25 @@ void WebPageProxy::updateActivityState(OptionSet<ActivityState::Flag> flagsToUpd
+ {
+     bool wasVisible = isViewVisible();
+     m_activityState.remove(flagsToUpdate);
++
++
++    if (m_activeForAutomation) {
++        if (*m_activeForAutomation) {
++            if (flagsToUpdate & ActivityState::IsFocused)
++                m_activityState.add(ActivityState::IsFocused);
++            if (flagsToUpdate & ActivityState::WindowIsActive)
++                m_activityState.add(ActivityState::WindowIsActive);
++            if (flagsToUpdate & ActivityState::IsVisible)
++                m_activityState.add(ActivityState::IsVisible);
++            if (flagsToUpdate & ActivityState::IsVisibleOrOccluded)
++                m_activityState.add(ActivityState::IsVisibleOrOccluded);
++        }
++        flagsToUpdate.remove(ActivityState::IsFocused);
++        flagsToUpdate.remove(ActivityState::WindowIsActive);
++        flagsToUpdate.remove(ActivityState::IsVisible);
++        flagsToUpdate.remove(ActivityState::IsVisibleOrOccluded);
++    }
++
+     if (flagsToUpdate & ActivityState::IsFocused && pageClient().isViewFocused())
+         m_activityState.add(ActivityState::IsFocused);
+     if (flagsToUpdate & ActivityState::WindowIsActive && pageClient().isViewWindowActive())
+@@ -2767,7 +2827,7 @@ static TrackingType mergeTrackingTypes(TrackingType a, TrackingType b)
  
  void WebPageProxy::updateTouchEventTracking(const WebTouchEvent& touchStartEvent)
  {
@@ -9297,7 +9351,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
      const EventNames& names = eventNames();
      for (auto& touchPoint : touchStartEvent.touchPoints()) {
          IntPoint location = touchPoint.location();
-@@ -2800,7 +2829,7 @@ void WebPageProxy::updateTouchEventTracking(const WebTouchEvent& touchStartEvent
+@@ -2800,7 +2860,7 @@ void WebPageProxy::updateTouchEventTracking(const WebTouchEvent& touchStartEvent
      m_touchAndPointerEventTracking.touchStartTracking = TrackingType::Synchronous;
      m_touchAndPointerEventTracking.touchMoveTracking = TrackingType::Synchronous;
      m_touchAndPointerEventTracking.touchEndTracking = TrackingType::Synchronous;
@@ -9306,7 +9360,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
  }
  
  TrackingType WebPageProxy::touchEventTrackingType(const WebTouchEvent& touchStartEvent) const
-@@ -3135,6 +3164,7 @@ void WebPageProxy::receivedNavigationPolicyDecision(PolicyAction policyAction, A
+@@ -3135,6 +3195,7 @@ void WebPageProxy::receivedNavigationPolicyDecision(PolicyAction policyAction, A
  
  void WebPageProxy::receivedPolicyDecision(PolicyAction action, API::Navigation* navigation, Optional<WebsitePoliciesData>&& websitePolicies, Ref<PolicyDecisionSender>&& sender, WillContinueLoadInNewProcess willContinueLoadInNewProcess)
  {
@@ -9314,7 +9368,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
      if (!hasRunningProcess()) {
          sender->send(PolicyAction::Ignore, 0, DownloadID(), WTF::nullopt);
          return;
-@@ -4228,6 +4258,7 @@ void WebPageProxy::didDestroyNavigation(uint64_t navigationID)
+@@ -4228,6 +4289,7 @@ void WebPageProxy::didDestroyNavigation(uint64_t navigationID)
  
      // FIXME: Message check the navigationID.
      m_navigationState->didDestroyNavigation(navigationID);
@@ -9322,7 +9376,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
  }
  
  void WebPageProxy::didStartProvisionalLoadForFrame(FrameIdentifier frameID, uint64_t navigationID, URL&& url, URL&& unreachableURL, const UserData& userData)
-@@ -4449,6 +4480,8 @@ void WebPageProxy::didFailProvisionalLoadForFrameShared(Ref<WebProcessProxy>&& p
+@@ -4449,6 +4511,8 @@ void WebPageProxy::didFailProvisionalLoadForFrameShared(Ref<WebProcessProxy>&& p
  
      m_failingProvisionalLoadURL = { };
  
@@ -9331,7 +9385,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
      // If the provisional page's load fails then we destroy the provisional page.
      if (m_provisionalPage && m_provisionalPage->mainFrame() == frame && willContinueLoading == WillContinueLoading::No)
          m_provisionalPage = nullptr;
-@@ -4886,8 +4919,16 @@ void WebPageProxy::decidePolicyForNavigationActionAsync(FrameIdentifier frameID,
+@@ -4886,8 +4950,16 @@ void WebPageProxy::decidePolicyForNavigationActionAsync(FrameIdentifier frameID,
      NavigationActionData&& navigationActionData, FrameInfoData&& frameInfoData, Optional<WebPageProxyIdentifier> originatingPageID, const WebCore::ResourceRequest& originalRequest, WebCore::ResourceRequest&& request,
      IPC::FormDataReference&& requestBody, WebCore::ResourceResponse&& redirectResponse, const UserData& userData, uint64_t listenerID)
  {
@@ -9350,7 +9404,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
  }
  
  void WebPageProxy::decidePolicyForNavigationActionAsyncShared(Ref<WebProcessProxy>&& process, PageIdentifier webPageID, FrameIdentifier frameID, WebCore::SecurityOriginData&& frameSecurityOrigin,
-@@ -5459,6 +5500,8 @@ void WebPageProxy::runJavaScriptAlert(FrameIdentifier frameID, SecurityOriginDat
+@@ -5459,6 +5531,8 @@ void WebPageProxy::runJavaScriptAlert(FrameIdentifier frameID, SecurityOriginDat
          if (auto* automationSession = process().processPool().automationSession())
              automationSession->willShowJavaScriptDialog(*this);
      }
@@ -9359,7 +9413,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
      m_uiClient->runJavaScriptAlert(*this, message, frame, WTFMove(securityOrigin), WTFMove(reply));
  }
  
-@@ -5478,6 +5521,8 @@ void WebPageProxy::runJavaScriptConfirm(FrameIdentifier frameID, SecurityOriginD
+@@ -5478,6 +5552,8 @@ void WebPageProxy::runJavaScriptConfirm(FrameIdentifier frameID, SecurityOriginD
          if (auto* automationSession = process().processPool().automationSession())
              automationSession->willShowJavaScriptDialog(*this);
      }
@@ -9368,7 +9422,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
  
      m_uiClient->runJavaScriptConfirm(*this, message, frame, WTFMove(securityOrigin), WTFMove(reply));
  }
-@@ -5497,6 +5542,8 @@ void WebPageProxy::runJavaScriptPrompt(FrameIdentifier frameID, SecurityOriginDa
+@@ -5497,6 +5573,8 @@ void WebPageProxy::runJavaScriptPrompt(FrameIdentifier frameID, SecurityOriginDa
          if (auto* automationSession = process().processPool().automationSession())
              automationSession->willShowJavaScriptDialog(*this);
      }
@@ -9377,7 +9431,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
  
      m_uiClient->runJavaScriptPrompt(*this, message, defaultValue, frame, WTFMove(securityOrigin), WTFMove(reply));
  }
-@@ -5656,6 +5703,8 @@ void WebPageProxy::runBeforeUnloadConfirmPanel(FrameIdentifier frameID, Security
+@@ -5656,6 +5734,8 @@ void WebPageProxy::runBeforeUnloadConfirmPanel(FrameIdentifier frameID, Security
              return;
          }
      }
@@ -9386,7 +9440,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
  
      // Since runBeforeUnloadConfirmPanel() can spin a nested run loop we need to turn off the responsiveness timer and the tryClose timer.
      m_process->stopResponsivenessTimer();
-@@ -6715,6 +6764,7 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
+@@ -6715,6 +6795,7 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
              if (auto* automationSession = process().processPool().automationSession())
                  automationSession->mouseEventsFlushedForPage(*this);
              didFinishProcessingAllPendingMouseEvents();
@@ -9394,7 +9448,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
          }
  
          break;
-@@ -6741,7 +6791,6 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
+@@ -6741,7 +6822,6 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
      case WebEvent::RawKeyDown:
      case WebEvent::Char: {
          LOG(KeyHandling, "WebPageProxy::didReceiveEvent: %s (queue empty %d)", webKeyboardEventTypeString(type), m_keyEventQueue.isEmpty());
@@ -9402,7 +9456,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
          MESSAGE_CHECK(m_process, !m_keyEventQueue.isEmpty());
          NativeWebKeyboardEvent event = m_keyEventQueue.takeFirst();
  
-@@ -6761,7 +6810,6 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
+@@ -6761,7 +6841,6 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
          // The call to doneWithKeyEvent may close this WebPage.
          // Protect against this being destroyed.
          Ref<WebPageProxy> protect(*this);
@@ -9410,7 +9464,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
          pageClient().doneWithKeyEvent(event, handled);
          if (!handled)
              m_uiClient->didNotHandleKeyEvent(this, event);
-@@ -6770,6 +6818,7 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
+@@ -6770,6 +6849,7 @@ void WebPageProxy::didReceiveEvent(uint32_t opaqueType, bool handled)
          if (!canProcessMoreKeyEvents) {
              if (auto* automationSession = process().processPool().automationSession())
                  automationSession->keyboardEventsFlushedForPage(*this);
@@ -9418,7 +9472,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
          }
          break;
      }
-@@ -7238,8 +7287,10 @@ static bool shouldReloadAfterProcessTermination(ProcessTerminationReason reason)
+@@ -7238,8 +7318,10 @@ static bool shouldReloadAfterProcessTermination(ProcessTerminationReason reason)
  void WebPageProxy::dispatchProcessDidTerminate(ProcessTerminationReason reason)
  {
      RELEASE_LOG_IF_ALLOWED(Loading, "dispatchProcessDidTerminate: reason = %d", reason);
@@ -9430,7 +9484,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
      if (m_loaderClient)
          handledByClient = reason != ProcessTerminationReason::RequestedByClient && m_loaderClient->processDidCrash(*this);
      else
-@@ -7712,6 +7763,14 @@ void WebPageProxy::gamepadActivity(const Vector<GamepadData>& gamepadDatas, bool
+@@ -7712,6 +7794,14 @@ void WebPageProxy::gamepadActivity(const Vector<GamepadData>& gamepadDatas, bool
  
  void WebPageProxy::didReceiveAuthenticationChallengeProxy(Ref<AuthenticationChallengeProxy>&& authenticationChallenge, NegotiatedLegacyTLS negotiatedLegacyTLS)
  {
@@ -9445,7 +9499,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
      if (negotiatedLegacyTLS == NegotiatedLegacyTLS::Yes) {
          m_navigationClient->shouldAllowLegacyTLS(*this, authenticationChallenge.get(), [this, protectedThis = makeRef(*this), authenticationChallenge = authenticationChallenge.copyRef()] (bool shouldAllowLegacyTLS) {
              if (shouldAllowLegacyTLS)
-@@ -7794,7 +7853,8 @@ void WebPageProxy::requestGeolocationPermissionForFrame(uint64_t geolocationID,
+@@ -7794,7 +7884,8 @@ void WebPageProxy::requestGeolocationPermissionForFrame(uint64_t geolocationID,
      MESSAGE_CHECK(m_process, securityOriginData);
  
      // FIXME: Geolocation should probably be using toString() as its string representation instead of databaseIdentifier().
@@ -9455,7 +9509,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
      auto request = m_geolocationPermissionRequestManager.createRequest(geolocationID);
      Function<void(bool)> completionHandler = [request = WTFMove(request)](bool allowed) {
          if (allowed)
-@@ -7802,6 +7862,11 @@ void WebPageProxy::requestGeolocationPermissionForFrame(uint64_t geolocationID,
+@@ -7802,6 +7893,11 @@ void WebPageProxy::requestGeolocationPermissionForFrame(uint64_t geolocationID,
          else
              request->deny();
      };
@@ -9468,7 +9522,7 @@ index 059e904a16c6c4b91d6271e25d239b975191facd..0c5038d790e2c5913b1bb8344e777205
      // FIXME: Once iOS migrates to the new WKUIDelegate SPI, clean this up
      // and make it one UIClient call that calls the completionHandler with false
 diff --git a/Source/WebKit/UIProcess/WebPageProxy.h b/Source/WebKit/UIProcess/WebPageProxy.h
-index b3856a4f9e7859bf3e0b9957c95040a784e9b317..5d51d3e9e03b375a2cbd01f909e9b27c3605f8e4 100644
+index b3856a4f9e7859bf3e0b9957c95040a784e9b317..2d154febc73de4877463e5099ffdc3002f6dfd2b 100644
 --- a/Source/WebKit/UIProcess/WebPageProxy.h
 +++ b/Source/WebKit/UIProcess/WebPageProxy.h
 @@ -35,6 +35,7 @@
@@ -9488,18 +9542,19 @@ index b3856a4f9e7859bf3e0b9957c95040a784e9b317..5d51d3e9e03b375a2cbd01f909e9b27c
  
  #if PLATFORM(IOS_FAMILY)
      void showInspectorIndication();
-@@ -555,6 +558,10 @@ public:
+@@ -555,6 +558,11 @@ public:
  
      void setPageLoadStateObserver(std::unique_ptr<PageLoadState::Observer>&&);
  
 +    void setAuthCredentialsForAutomation(Optional<WebCore::Credential>&&);
 +    void setPermissionsForAutomation(const HashMap<String, HashSet<String>>&);
++    void setActiveForAutomation(Optional<bool> active);
 +    void logToStderr(const String& str);
 +
      void initializeWebPage();
      void setDrawingArea(std::unique_ptr<DrawingAreaProxy>&&);
  
-@@ -580,6 +587,7 @@ public:
+@@ -580,6 +588,7 @@ public:
      void closePage();
  
      void addPlatformLoadParameters(LoadParameters&);
@@ -9507,7 +9562,7 @@ index b3856a4f9e7859bf3e0b9957c95040a784e9b317..5d51d3e9e03b375a2cbd01f909e9b27c
      RefPtr<API::Navigation> loadRequest(WebCore::ResourceRequest&&, WebCore::ShouldOpenExternalURLsPolicy = WebCore::ShouldOpenExternalURLsPolicy::ShouldAllowExternalSchemes, API::Object* userData = nullptr);
      RefPtr<API::Navigation> loadFile(const String& fileURL, const String& resourceDirectoryURL, API::Object* userData = nullptr);
      RefPtr<API::Navigation> loadData(const IPC::DataReference&, const String& MIMEType, const String& encoding, const String& baseURL, API::Object* userData = nullptr, WebCore::ShouldOpenExternalURLsPolicy = WebCore::ShouldOpenExternalURLsPolicy::ShouldNotAllow);
-@@ -2293,6 +2301,7 @@ private:
+@@ -2293,6 +2302,7 @@ private:
      String m_overrideContentSecurityPolicy;
  
      RefPtr<WebInspectorProxy> m_inspector;
@@ -9515,12 +9570,13 @@ index b3856a4f9e7859bf3e0b9957c95040a784e9b317..5d51d3e9e03b375a2cbd01f909e9b27c
  
  #if ENABLE(FULLSCREEN_API)
      std::unique_ptr<WebFullScreenManagerProxy> m_fullScreenManager;
-@@ -2707,6 +2716,8 @@ private:
+@@ -2707,6 +2717,9 @@ private:
      bool m_isLayerTreeFrozenDueToSwipeAnimation { false };
      
      String m_overriddenMediaType;
 +    Optional<WebCore::Credential> m_credentialsForAutomation;
 +    HashMap<String, HashSet<String>> m_permissionsForAutomation;
++    Optional<bool> m_activeForAutomation;
          
  #if PLATFORM(IOS_FAMILY) && ENABLE(DEVICE_ORIENTATION)
      std::unique_ptr<WebDeviceOrientationUpdateProviderProxy> m_webDeviceOrientationUpdateProviderProxy;
@@ -12529,7 +12585,7 @@ index f84e5cde0baaa08dab1fc77771e4a62a08a5df78..dac73d3d9db04c5d502432cea8adfa89
      void navigateToHistory(UINT menuID);
      bool seedInitialDefaultPreferences();
 diff --git a/Tools/MiniBrowser/win/WinMain.cpp b/Tools/MiniBrowser/win/WinMain.cpp
-index b1d17e88de61a6f196830f62604e4174564506bd..0cc40ce5a5f0a3331275fcdaf7ea95cd0dc5031f 100644
+index b1d17e88de61a6f196830f62604e4174564506bd..2035067fef157cb23dc3a93f1a086719a32d7d38 100644
 --- a/Tools/MiniBrowser/win/WinMain.cpp
 +++ b/Tools/MiniBrowser/win/WinMain.cpp
 @@ -32,6 +32,9 @@
@@ -12587,7 +12643,18 @@ index b1d17e88de61a6f196830f62604e4174564506bd..0cc40ce5a5f0a3331275fcdaf7ea95cd
  
      if (options.useFullDesktop)
          computeFullDesktopFrame();
-@@ -86,19 +115,35 @@ int WINAPI wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance,
+@@ -75,9 +104,7 @@ int WINAPI wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance,
+     OleInitialize(nullptr);
+ 
+     if (SetProcessDpiAwarenessContextPtr())
+-        SetProcessDpiAwarenessContextPtr()(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
+-    else
+-        ::SetProcessDPIAware();
++        SetProcessDpiAwarenessContextPtr()(DPI_AWARENESS_CONTEXT_UNAWARE);
+ 
+ #if !ENABLE(WEBKIT_LEGACY)
+     auto factory = WebKitBrowserWindow::create;
+@@ -86,19 +113,35 @@ int WINAPI wWinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance,
  #else
      auto factory = options.windowType == BrowserWindowType::WebKit ? WebKitBrowserWindow::create : WebKitLegacyBrowserWindow::create;
  #endif
diff --git a/docs/api.md b/docs/api.md
index b946c1790a..fb8e257c48 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -153,13 +153,12 @@ See [ChromiumBrowser], [FirefoxBrowser] and [WebKitBrowser] for browser-specific
 - [browser.isConnected()](#browserisconnected)
 - [browser.newContext(options)](#browsernewcontextoptions)
 - [browser.newPage([options])](#browsernewpageoptions)
-- [browser.pages()](#browserpages)
 <!-- GEN:stop -->
 
 #### event: 'disconnected'
 Emitted when Browser gets disconnected from the browser application. This might happen because of one of the following:
 - Browser application is closed or crashed.
-- The [`browser.disconnect`](#browserdisconnect) method was called.
+- The [`browser.close`](#browserclose) method was called.
 
 #### browser.close()
 - returns: <[Promise]>
@@ -233,12 +232,9 @@ Creates a new browser context. It won't share cookies/cache with other browser c
   - `permissions` <[Object]> A map from origin keys to permissions values. See [browserContext.setPermissions](#browsercontextsetpermissionsorigin-permissions) for more details.
 - returns: <[Promise]<[Page]>>
 
-Creates a new page in a new browser context.
+Creates a new page in a new browser context. Closing this page will close the context as well.
 
-#### browser.pages()
-- returns: <[Promise]<[Array]<[Page]>>> Promise which resolves to an array of all open pages.
-
-An array of all the pages inside all the browser contexts.
+This is a convenience API that should only be used for the single-page scenarios and short snippets. Production code and testing frameworks should explicitly create [browser.newContext](#browsernewcontextoptions) followed by the [browserContext.newPage](#browsercontextnewpage) to control their exact life times.
 
 ### class: BrowserContext
 
@@ -263,6 +259,7 @@ await context.close();
 ```
 
 <!-- GEN:toc -->
+- [event: 'close'](#event-close)
 - [browserContext.clearCookies()](#browsercontextclearcookies)
 - [browserContext.clearPermissions()](#browsercontextclearpermissions)
 - [browserContext.close()](#browsercontextclose)
@@ -274,6 +271,13 @@ await context.close();
 - [browserContext.setPermissions(origin, permissions[])](#browsercontextsetpermissionsorigin-permissions)
 <!-- GEN:stop -->
 
+#### event: 'close'
+
+Emitted when Browser context gets closed. This might happen because of one of the following:
+- Browser context is closed.
+- Browser application is closed or crashed.
+- The [`browser.close`](#browserclose) method was called.
+
 #### browserContext.clearCookies()
 - returns: <[Promise]>
 
@@ -426,7 +430,7 @@ page.removeListener('request', logRequest);
 ```
 
 <!-- GEN:toc -->
-- [event: 'close'](#event-close)
+- [event: 'close'](#event-close-1)
 - [event: 'console'](#event-console)
 - [event: 'dialog'](#event-dialog)
 - [event: 'domcontentloaded'](#event-domcontentloaded)
@@ -448,7 +452,7 @@ page.removeListener('request', logRequest);
 - [page.$$(selector)](#pageselector-1)
 - [page.$$eval(selector, pageFunction[, ...args])](#pageevalselector-pagefunction-args)
 - [page.$eval(selector, pageFunction[, ...args])](#pageevalselector-pagefunction-args-1)
-- [page.$wait(selector, pageFunction[, options[, ...args]])](#pagewaitselector-pagefunction-options-args)
+- [page.$wait(selector[, options])](#pagewaitselector-options)
 - [page.accessibility](#pageaccessibility)
 - [page.addScriptTag(options)](#pageaddscripttagoptions)
 - [page.addStyleTag(options)](#pageaddstyletagoptions)
@@ -679,23 +683,24 @@ const html = await page.$eval('.main-container', e => e.outerHTML);
 
 Shortcut for [page.mainFrame().$eval(selector, pageFunction)](#frameevalselector-pagefunction-args).
 
-#### page.$wait(selector, pageFunction[, options[, ...args]])
-- `selector` <[string]> A selector to query page for
-- `pageFunction` <[function]\([Element]\)> Function to be evaluated in browser context
-- `options` <[Object]> Optional waiting parameters
-  - `polling` <[number]|"raf"|"mutation"> An interval at which the `pageFunction` is executed, defaults to `raf`. If `polling` is a number, then it is treated as an interval in milliseconds at which the function would be executed. If `polling` is a string, then it can be one of the following values:
-    - `'raf'` - to constantly execute `pageFunction` in `requestAnimationFrame` callback. This is the tightest polling mode which is suitable to observe styling changes.
-    - `'mutation'` - to execute `pageFunction` on every DOM mutation.
-  - `timeout` <[number]> maximum time to wait for in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout. The default value can be changed by using the [page.setDefaultTimeout(timeout)](#pagesetdefaulttimeouttimeout) method.
-- `...args` <...[Serializable]|[JSHandle]> Arguments to pass to  `pageFunction`
-- returns: <[Promise]<[JSHandle]>> Promise which resolves to a JSHandle of the success value
+#### page.$wait(selector[, options])
+- `selector` <[string]> A selector of an element to wait for
+- `options` <[Object]>
+  - `visibility` <"visible"|"hidden"|"any"> Wait for element to become visible (`visible`), hidden (`hidden`), present in dom (`any`). Defaults to `any`.
+  - `timeout` <[number]> Maximum time in milliseconds, defaults to 30 seconds, pass `0` to disable timeout. The default value can be changed by using the [page.setDefaultTimeout(timeout)](#pagesetdefaulttimeouttimeout) method.
+- returns: <[Promise]<?[ElementHandle]>> Promise which resolves when element specified by selector string is added to DOM. Resolves to `null` if waiting for `hidden: true` and selector is not found in DOM.
 
-This method runs `document.querySelector` within the page and passes it as the first argument to `pageFunction`. If there's no element matching `selector`, the method throws an error.
+Wait for the `selector` to appear in page. If at the moment of calling
+the method the `selector` already exists, the method will return
+immediately. If the selector doesn't appear after the `timeout` milliseconds of waiting, the function will throw.
 
-If `pageFunction` returns a [Promise], then `page.$wait` would wait for the promise to resolve and return its value. The function
-is being called on the element periodically until either timeout expires or the function returns the truthy value.
+This method works across navigations:
+```js
+const handle = await page.$wait(selector);
+await handle.click();
+```
 
-Shortcut for [page.mainFrame().$wait(selector, pageFunction[, options[, ...args]])](#framewaitselector-pagefunction-options-args).
+This is a shortcut to [page.waitForSelector(selector[, options])](#pagewaitforselectorselector-options).
 
 #### page.accessibility
 - returns: <[Accessibility]>
@@ -1664,7 +1669,7 @@ An example of getting text from an iframe element:
 - [frame.$$(selector)](#frameselector-1)
 - [frame.$$eval(selector, pageFunction[, ...args])](#frameevalselector-pagefunction-args)
 - [frame.$eval(selector, pageFunction[, ...args])](#frameevalselector-pagefunction-args-1)
-- [frame.$wait(selector, pageFunction[, options[, ...args]])](#framewaitselector-pagefunction-options-args)
+- [frame.$wait(selector[, options])](#framewaitselector-options)
 - [frame.addScriptTag(options)](#frameaddscripttagoptions)
 - [frame.addStyleTag(options)](#frameaddstyletagoptions)
 - [frame.check(selector, [options])](#framecheckselector-options)
@@ -1740,21 +1745,24 @@ const preloadHref = await frame.$eval('link[rel=preload]', el => el.href);
 const html = await frame.$eval('.main-container', e => e.outerHTML);
 ```
 
-#### frame.$wait(selector, pageFunction[, options[, ...args]])
-- `selector` <[string]> A selector to query page for
-- `pageFunction` <[function]\([Element]\)> Function to be evaluated in browser context
-- `options` <[Object]> Optional waiting parameters
-  - `polling` <[number]|"raf"|"mutation"> An interval at which the `pageFunction` is executed, defaults to `raf`. If `polling` is a number, then it is treated as an interval in milliseconds at which the function would be executed. If `polling` is a string, then it can be one of the following values:
-    - `'raf'` - to constantly execute `pageFunction` in `requestAnimationFrame` callback. This is the tightest polling mode which is suitable to observe styling changes.
-    - `'mutation'` - to execute `pageFunction` on every DOM mutation.
-  - `timeout` <[number]> maximum time to wait for in milliseconds. Defaults to `30000` (30 seconds). Pass `0` to disable timeout. The default value can be changed by using the [page.setDefaultTimeout(timeout)](#pagesetdefaulttimeouttimeout) method.
-- `...args` <...[Serializable]|[JSHandle]> Arguments to pass to  `pageFunction`
-- returns: <[Promise]<[JSHandle]>> Promise which resolves to a JSHandle of the success value
+#### frame.$wait(selector[, options])
+- `selector` <[string]> A selector of an element to wait for
+- `options` <[Object]>
+  - `visibility` <"visible"|"hidden"|"any"> Wait for element to become visible (`visible`), hidden (`hidden`), present in dom (`any`). Defaults to `any`.
+  - `timeout` <[number]> Maximum time in milliseconds, defaults to 30 seconds, pass `0` to disable timeout. The default value can be changed by using the [page.setDefaultTimeout(timeout)](#pagesetdefaulttimeouttimeout) method.
+- returns: <[Promise]<?[ElementHandle]>> Promise which resolves when element specified by selector string is added to DOM. Resolves to `null` if waiting for `hidden: true` and selector is not found in DOM.
 
-This method runs `document.querySelector` within the frame and passes it as the first argument to `pageFunction`. If there's no element matching `selector`, the method throws an error.
+Wait for the `selector` to appear in page. If at the moment of calling
+the method the `selector` already exists, the method will return
+immediately. If the selector doesn't appear after the `timeout` milliseconds of waiting, the function will throw.
 
-If `pageFunction` returns a [Promise], then `page.$wait` would wait for the promise to resolve and return its value. The function
-is being called on the element periodically until either timeout expires or the function returns the truthy value.
+This method works across navigations:
+```js
+const handle = await page.$wait(selector);
+await handle.click();
+```
+
+This is a shortcut to [frame.waitForSelector(selector[, options])](#framewaitforselectorselector-options).
 
 #### frame.addScriptTag(options)
 - `options` <[Object]>
@@ -3168,7 +3176,7 @@ const { selectors, firefox } = require('playwright');  // Or 'chromium' or 'webk
 The [WebSocket] class represents websocket connections in the page.
 
 <!-- GEN:toc -->
-- [event: 'close'](#event-close-1)
+- [event: 'close'](#event-close-2)
 - [event: 'error'](#event-error)
 - [event: 'messageReceived'](#event-messagereceived)
 - [event: 'messageSent'](#event-messagesent)
@@ -3423,7 +3431,7 @@ If the function passed to the `worker.evaluateHandle` returns a [Promise], then
 ### class: BrowserServer
 
 <!-- GEN:toc -->
-- [event: 'close'](#event-close-2)
+- [event: 'close'](#event-close-3)
 - [browserServer.close()](#browserserverclose)
 - [browserServer.kill()](#browserserverkill)
 - [browserServer.process()](#browserserverprocess)
@@ -3470,6 +3478,7 @@ const { chromium } = require('playwright');  // Or 'firefox' or 'webkit'.
 <!-- GEN:toc -->
 - [browserType.connect(options)](#browsertypeconnectoptions)
 - [browserType.devices](#browsertypedevices)
+- [browserType.downloadBrowserIfNeeded([progress])](#browsertypedownloadbrowserifneededprogress)
 - [browserType.errors](#browsertypeerrors)
 - [browserType.executablePath()](#browsertypeexecutablepath)
 - [browserType.launch([options])](#browsertypelaunchoptions)
@@ -3508,6 +3517,12 @@ const iPhone = webkit.devices['iPhone 6'];
 })();
 ```
 
+#### browserType.downloadBrowserIfNeeded([progress])
+- `progress` <[function]> If download is initiated, this function is called with two parameters: `downloadedBytes` and `totalBytes`.
+- returns: <[Promise]> promise that resolves when browser is successfully downloaded.
+
+Download browser binary if it is missing.
+
 #### browserType.errors
 - returns: <[Object]>
   - `TimeoutError` <[function]> A class of [TimeoutError].
@@ -3652,7 +3667,6 @@ await browser.stopTracing();
 - [browser.isConnected()](#browserisconnected)
 - [browser.newContext(options)](#browsernewcontextoptions)
 - [browser.newPage([options])](#browsernewpageoptions)
-- [browser.pages()](#browserpages)
 <!-- GEN:stop -->
 
 #### event: 'targetchanged'
@@ -3819,7 +3833,6 @@ Firefox browser instance does not expose Firefox-specific features.
 - [browser.isConnected()](#browserisconnected)
 - [browser.newContext(options)](#browsernewcontextoptions)
 - [browser.newPage([options])](#browsernewpageoptions)
-- [browser.pages()](#browserpages)
 <!-- GEN:stop -->
 
 ### class: WebKitBrowser
@@ -3835,7 +3848,6 @@ WebKit browser instance does not expose WebKit-specific features.
 - [browser.isConnected()](#browserisconnected)
 - [browser.newContext(options)](#browsernewcontextoptions)
 - [browser.newPage([options])](#browsernewpageoptions)
-- [browser.pages()](#browserpages)
 <!-- GEN:stop -->
 
 ### Working with selectors
diff --git a/download-browser.js b/download-browser.js
index 5cbb6ba5ca..c2a72e755e 100644
--- a/download-browser.js
+++ b/download-browser.js
@@ -38,7 +38,7 @@ async function downloadBrowser(browser) {
   // Do nothing if the revision is already downloaded.
   if (revisionInfo.local)
     return revisionInfo;
-  await fetcher.download(revisionInfo.revision, onProgress);
+  await browserType.downloadBrowserIfNeeded(onProgress);
   logPolitely(`${browser} downloaded to ${revisionInfo.folderPath}`);
   return revisionInfo;
 }
diff --git a/package.json b/package.json
index e29bdecaeb..1483882b14 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
   },
   "main": "index.js",
   "playwright": {
-    "chromium_revision": "739261",
+    "chromium_revision": "740289",
     "firefox_revision": "1028",
     "webkit_revision": "1141"
   },
diff --git a/src/browser.ts b/src/browser.ts
index 905f5ee2f8..b5cca25331 100644
--- a/src/browser.ts
+++ b/src/browser.ts
@@ -21,11 +21,9 @@ import { Page } from './page';
 export interface Browser extends platform.EventEmitterType {
   newContext(options?: BrowserContextOptions): Promise<BrowserContext>;
   contexts(): BrowserContext[];
-  pages(): Promise<Page[]>;
   newPage(options?: BrowserContextOptions): Promise<Page>;
   isConnected(): boolean;
   close(): Promise<void>;
-  _defaultContext: BrowserContext | undefined;
 }
 
 export type ConnectOptions = {
@@ -33,14 +31,11 @@ export type ConnectOptions = {
   wsEndpoint: string
 };
 
-export async function collectPages(browser: Browser): Promise<Page[]> {
-  const result: Promise<Page[]>[] = [];
-  for (const browserContext of browser.contexts())
-    result.push(browserContext.pages());
-  const pages: Page[] = [];
-  for (const group of await Promise.all(result))
-    pages.push(...group);
-  return pages;
+export async function createPageInNewContext(browser: Browser, options?: BrowserContextOptions): Promise<Page> {
+  const context = await browser.newContext(options);
+  const page = await context.newPage();
+  page._ownedContext = context;
+  return page;
 }
 
 export type LaunchType = 'local' | 'server' | 'persistent';
diff --git a/src/browserContext.ts b/src/browserContext.ts
index 86753436ad..ca56d75520 100644
--- a/src/browserContext.ts
+++ b/src/browserContext.ts
@@ -19,6 +19,8 @@ import { Page } from './page';
 import * as network from './network';
 import * as types from './types';
 import { helper } from './helper';
+import * as platform from './platform';
+import { Events } from './events';
 
 export interface BrowserContextDelegate {
   pages(): Promise<Page[]>;
@@ -47,12 +49,13 @@ export type BrowserContextOptions = {
   permissions?: { [key: string]: string[] };
 };
 
-export class BrowserContext {
+export class BrowserContext extends platform.EventEmitter {
   private readonly _delegate: BrowserContextDelegate;
   readonly _options: BrowserContextOptions;
   private _closed = false;
 
   constructor(delegate: BrowserContextDelegate, options: BrowserContextOptions) {
+    super();
     this._delegate = delegate;
     this._options = { ...options };
     if (!this._options.viewport && this._options.viewport !== null)
@@ -79,6 +82,11 @@ export class BrowserContext {
   }
 
   async newPage(): Promise<Page> {
+    const pages = this._delegate.existingPages();
+    for (const page of pages) {
+      if (page._ownedContext)
+        throw new Error('Please use browser.newContext() for multi-page scripts that share the context.');
+    }
     return this._delegate.newPage();
   }
 
@@ -114,12 +122,20 @@ export class BrowserContext {
       return;
     await this._delegate.close();
     this._closed = true;
+    this.emit(Events.BrowserContext.Close);
   }
 
   static validateOptions(options: BrowserContextOptions) {
     if (options.geolocation)
       verifyGeolocation(options.geolocation);
   }
+
+  _browserClosed() {
+    this._closed = true;
+    for (const page of this._delegate.existingPages())
+      page._didClose();
+    this.emit(Events.BrowserContext.Close);
+  }
 }
 
 function verifyGeolocation(geolocation: types.Geolocation): types.Geolocation {
diff --git a/src/chromium/crBrowser.ts b/src/chromium/crBrowser.ts
index 5bc2987cb4..755b85525c 100644
--- a/src/chromium/crBrowser.ts
+++ b/src/chromium/crBrowser.ts
@@ -24,7 +24,7 @@ import { Page, Worker } from '../page';
 import { CRTarget } from './crTarget';
 import { Protocol } from './protocol';
 import { CRPage } from './crPage';
-import { Browser, collectPages } from '../browser';
+import { Browser, createPageInNewContext } from '../browser';
 import * as network from '../network';
 import * as types from '../types';
 import * as platform from '../platform';
@@ -56,7 +56,11 @@ export class CRBrowser extends platform.EventEmitter implements Browser {
     this._client = connection.rootSession;
 
     this._defaultContext = this._createBrowserContext(null, {});
-    this._connection.on(ConnectionEvents.Disconnected, () => this.emit(CommonEvents.Browser.Disconnected));
+    this._connection.on(ConnectionEvents.Disconnected, () => {
+      for (const context of this.contexts())
+        context._browserClosed();
+      this.emit(CommonEvents.Browser.Disconnected);
+    });
     this._client.on('Target.targetCreated', this._targetCreated.bind(this));
     this._client.on('Target.targetDestroyed', this._targetDestroyed.bind(this));
     this._client.on('Target.targetInfoChanged', this._targetInfoChanged.bind(this));
@@ -164,13 +168,8 @@ export class CRBrowser extends platform.EventEmitter implements Browser {
     return Array.from(this._contexts.values());
   }
 
-  async pages(): Promise<Page[]> {
-    return collectPages(this);
-  }
-
   async newPage(options?: BrowserContextOptions): Promise<Page> {
-    const context = await this.newContext(options);
-    return context.newPage();
+    return createPageInNewContext(this, options);
   }
 
   async _targetCreated(event: Protocol.Target.targetCreatedPayload) {
diff --git a/src/chromium/crPage.ts b/src/chromium/crPage.ts
index 49ea276fbc..63a1ba099c 100644
--- a/src/chromium/crPage.ts
+++ b/src/chromium/crPage.ts
@@ -484,6 +484,17 @@ export class CRPage implements PageDelegate {
     return {x, y, width, height};
   }
 
+  async scrollRectIntoViewIfNeeded(handle: dom.ElementHandle, rect?: types.Rect): Promise<void> {
+    await this._client.send('DOM.scrollIntoViewIfNeeded', {
+      objectId: toRemoteObject(handle).objectId,
+      rect,
+    }).catch(e => {
+      if (e instanceof Error && e.message.includes('Node does not have a layout object'))
+        e.message = 'Node is either not visible or not an HTMLElement';
+      throw e;
+    });
+  }
+
   async getContentQuads(handle: dom.ElementHandle): Promise<types.Quad[] | null> {
     const result = await this._client.send('DOM.getContentQuads', {
       objectId: toRemoteObject(handle).objectId
diff --git a/src/dom.ts b/src/dom.ts
index 5a581ae945..ab2c3a05fa 100644
--- a/src/dom.ts
+++ b/src/dom.ts
@@ -160,58 +160,12 @@ export class ElementHandle<T extends Node = Node> extends js.JSHandle<T> {
     return this._page._delegate.getContentFrame(this);
   }
 
-  async scrollIntoViewIfNeeded() {
-    const error = await this._evaluateInUtility(async (node: Node, pageJavascriptEnabled: boolean) => {
-      if (!node.isConnected)
-        return 'Node is detached from document';
-      if (node.nodeType !== Node.ELEMENT_NODE)
-        return 'Node is not of type HTMLElement';
-      const element = node as Element;
-      // force-scroll if page's javascript is disabled.
-      if (!pageJavascriptEnabled) {
-        // @ts-ignore because only Chromium still supports 'instant'
-        element.scrollIntoView({block: 'center', inline: 'center', behavior: 'instant'});
-        return false;
-      }
-      const visibleRatio = await new Promise(resolve => {
-        const observer = new IntersectionObserver(entries => {
-          resolve(entries[0].intersectionRatio);
-          observer.disconnect();
-        });
-        observer.observe(element);
-        // Firefox doesn't call IntersectionObserver callback unless
-        // there are rafs.
-        requestAnimationFrame(() => {});
-      });
-      if (visibleRatio !== 1.0) {
-        // @ts-ignore because only Chromium still supports 'instant'
-        element.scrollIntoView({block: 'center', inline: 'center', behavior: 'instant'});
-      }
-      return false;
-    }, !!this._page.context()._options.javaScriptEnabled);
-    if (error)
-      throw new Error(error);
+  async _scrollRectIntoViewIfNeeded(rect?: types.Rect): Promise<void> {
+    await this._page._delegate.scrollRectIntoViewIfNeeded(this, rect);
   }
 
-  private async _ensurePointerActionPoint(relativePoint?: types.Point): Promise<types.Point> {
-    await this.scrollIntoViewIfNeeded();
-    if (!relativePoint)
-      return this._clickablePoint();
-    let r = await this._viewportPointAndScroll(relativePoint);
-    if (r.scrollX || r.scrollY) {
-      const error = await this._evaluateInUtility((element, scrollX, scrollY) => {
-        if (!element.ownerDocument || !element.ownerDocument.defaultView)
-          return 'Node does not have a containing window';
-        element.ownerDocument.defaultView.scrollBy(scrollX, scrollY);
-        return false;
-      }, r.scrollX, r.scrollY);
-      if (error)
-        throw new Error(error);
-      r = await this._viewportPointAndScroll(relativePoint);
-      if (r.scrollX || r.scrollY)
-        throw new Error('Failed to scroll relative point into viewport');
-    }
-    return r.point;
+  async scrollIntoViewIfNeeded() {
+    await this._scrollRectIntoViewIfNeeded();
   }
 
   private async _clickablePoint(): Promise<types.Point> {
@@ -253,7 +207,7 @@ export class ElementHandle<T extends Node = Node> extends js.JSHandle<T> {
     return result;
   }
 
-  private async _viewportPointAndScroll(relativePoint: types.Point): Promise<{point: types.Point, scrollX: number, scrollY: number}> {
+  private async _relativePoint(relativePoint: types.Point): Promise<types.Point> {
     const [box, border] = await Promise.all([
       this.boundingBox(),
       this._evaluateInUtility((node: Node) => {
@@ -273,23 +227,13 @@ export class ElementHandle<T extends Node = Node> extends js.JSHandle<T> {
       point.x += border.x;
       point.y += border.y;
     }
-    const metrics = await this._page._delegate.layoutViewport();
-    // Give 20 extra pixels to avoid any issues on viewport edge.
-    let scrollX = 0;
-    if (point.x < 20)
-      scrollX = point.x - 20;
-    if (point.x > metrics.width - 20)
-      scrollX = point.x - metrics.width + 20;
-    let scrollY = 0;
-    if (point.y < 20)
-      scrollY = point.y - 20;
-    if (point.y > metrics.height - 20)
-      scrollY = point.y - metrics.height + 20;
-    return { point, scrollX, scrollY };
+    return point;
   }
 
   async _performPointerAction(action: (point: types.Point) => Promise<void>, options?: input.PointerActionOptions): Promise<void> {
-    const point = await this._ensurePointerActionPoint(options ? options.relativePoint : undefined);
+    const relativePoint = options ? options.relativePoint : undefined;
+    await this._scrollRectIntoViewIfNeeded(relativePoint ? { x: relativePoint.x, y: relativePoint.y, width: 0, height: 0 } : undefined);
+    const point = relativePoint ? await this._relativePoint(relativePoint) : await this._clickablePoint();
     let restoreModifiers: input.Modifier[] | undefined;
     if (options && options.modifiers)
       restoreModifiers = await this._page.keyboard._ensureModifiers(options.modifiers);
diff --git a/src/events.ts b/src/events.ts
index a5d9f751ea..462b772e51 100644
--- a/src/events.ts
+++ b/src/events.ts
@@ -20,6 +20,10 @@ export const Events = {
     Disconnected: 'disconnected'
   },
 
+  BrowserContext: {
+    Close: 'close'
+  },
+
   BrowserServer: {
     Close: 'close',
   },
diff --git a/src/firefox/ffBrowser.ts b/src/firefox/ffBrowser.ts
index 531e2fe50e..6fc992abb5 100644
--- a/src/firefox/ffBrowser.ts
+++ b/src/firefox/ffBrowser.ts
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import { Browser, collectPages } from '../browser';
+import { Browser, createPageInNewContext } from '../browser';
 import { BrowserContext, BrowserContextOptions } from '../browserContext';
 import { Events } from '../events';
 import { assert, helper, RegisteredListener, debugError } from '../helper';
@@ -50,8 +50,11 @@ export class FFBrowser extends platform.EventEmitter implements Browser {
 
     this._defaultContext = this._createBrowserContext(null, {});
     this._contexts = new Map();
-    this._connection.on(ConnectionEvents.Disconnected, () => this.emit(Events.Browser.Disconnected));
-
+    this._connection.on(ConnectionEvents.Disconnected, () => {
+      for (const context of this.contexts())
+        context._browserClosed();
+      this.emit(Events.Browser.Disconnected);
+    });
     this._eventListeners = [
       helper.addEventListener(this._connection, 'Target.targetCreated', this._onTargetCreated.bind(this)),
       helper.addEventListener(this._connection, 'Target.targetDestroyed', this._onTargetDestroyed.bind(this)),
@@ -90,13 +93,8 @@ export class FFBrowser extends platform.EventEmitter implements Browser {
     return Array.from(this._contexts.values());
   }
 
-  async pages(): Promise<Page[]> {
-    return collectPages(this);
-  }
-
   async newPage(options?: BrowserContextOptions): Promise<Page> {
-    const context = await this.newContext(options);
-    return context.newPage();
+    return createPageInNewContext(this, options);
   }
 
   async _waitForTarget(predicate: (target: Target) => boolean, options: { timeout?: number; } = {}): Promise<Target> {
diff --git a/src/firefox/ffPage.ts b/src/firefox/ffPage.ts
index eb9a274c78..4780a528de 100644
--- a/src/firefox/ffPage.ts
+++ b/src/firefox/ffPage.ts
@@ -392,6 +392,14 @@ export class FFPage implements PageDelegate {
     return { x: minX, y: minY, width: maxX - minX, height: maxY - minY };
   }
 
+  async scrollRectIntoViewIfNeeded(handle: dom.ElementHandle, rect?: types.Rect): Promise<void> {
+    await this._session.send('Page.scrollIntoViewIfNeeded', {
+      frameId: handle._context.frame._id,
+      objectId: toRemoteObject(handle).objectId!,
+      rect,
+    });
+  }
+
   async getContentQuads(handle: dom.ElementHandle): Promise<types.Quad[] | null> {
     const result = await this._session.send('Page.getContentQuads', {
       frameId: handle._context.frame._id,
diff --git a/src/frames.ts b/src/frames.ts
index 39959e2162..eb5db37217 100644
--- a/src/frames.ts
+++ b/src/frames.ts
@@ -620,6 +620,10 @@ export class Frame {
     return handle;
   }
 
+  async $wait(selector: string, options?: types.TimeoutOptions & { visibility?: types.Visibility }): Promise<dom.ElementHandle<Element> | null> {
+    return this.waitForSelector(selector, options);
+  }
+
   $eval: types.$Eval = async (selector, pageFunction, ...args) => {
     const context = await this._mainContext();
     const elementHandle = await context._$(selector);
@@ -938,12 +942,6 @@ export class Frame {
     return this._scheduleRerunnableTask(task, 'main', options.timeout);
   }
 
-  $wait: types.$Wait = async (selector, pageFunction, options, ...args) => {
-    options = { timeout: this._page._timeoutSettings.timeout(), ...(options || {}) };
-    const task = dom.waitForFunctionTask(selector, pageFunction, options, ...args);
-    return this._scheduleRerunnableTask(task, 'main', options.timeout) as any;
-  }
-
   async title(): Promise<string> {
     const context = await this._utilityContext();
     return context.evaluate(() => document.title);
diff --git a/src/page.ts b/src/page.ts
index 394eac87c6..3e899647f5 100644
--- a/src/page.ts
+++ b/src/page.ts
@@ -69,6 +69,7 @@ export interface PageDelegate {
   setInputFiles(handle: dom.ElementHandle<HTMLInputElement>, files: types.FilePayload[]): Promise<void>;
   getBoundingBox(handle: dom.ElementHandle): Promise<types.Rect | null>;
   getFrameElement(frame: frames.Frame): Promise<dom.ElementHandle>;
+  scrollRectIntoViewIfNeeded(handle: dom.ElementHandle, rect?: types.Rect): Promise<void>;
 
   getAccessibilityTree(needle?: dom.ElementHandle): Promise<{tree: accessibility.AXNode, needle: accessibility.AXNode | null}>;
   pdf?: (options?: types.PDFOptions) => Promise<platform.BufferType>;
@@ -113,6 +114,7 @@ export class Page extends platform.EventEmitter {
   readonly pdf: ((options?: types.PDFOptions) => Promise<platform.BufferType>) | undefined;
   readonly coverage: Coverage | undefined;
   readonly _requestHandlers: { url: types.URLMatch, handler: (request: network.Request) => void }[] = [];
+  _ownedContext: BrowserContext | undefined;
 
   constructor(delegate: PageDelegate, browserContext: BrowserContext) {
     super();
@@ -213,6 +215,10 @@ export class Page extends platform.EventEmitter {
     return this.mainFrame().waitForSelector(selector, options);
   }
 
+  async $wait(selector: string, options?: types.TimeoutOptions & { visibility?: types.Visibility }): Promise<dom.ElementHandle<Element> | null> {
+    return this.waitForSelector(selector, options);
+  }
+
   evaluateHandle: types.EvaluateHandle = async (pageFunction, ...args) => {
     return this.mainFrame().evaluateHandle(pageFunction, ...args as any);
   }
@@ -471,6 +477,8 @@ export class Page extends platform.EventEmitter {
     await this._delegate.closePage(runBeforeUnload);
     if (!runBeforeUnload)
       await this._closedPromise;
+    if (this._ownedContext)
+      await this._ownedContext.close();
   }
 
   isClosed(): boolean {
@@ -525,10 +533,6 @@ export class Page extends platform.EventEmitter {
     return this.mainFrame().waitForFunction(pageFunction, options, ...args);
   }
 
-  $wait: types.$Wait = async (selector, pageFunction, options, ...args) => {
-    return this.mainFrame().$wait(selector, pageFunction, options, ...args as any);
-  }
-
   workers(): Worker[] {
     return [...this._workers.values()];
   }
diff --git a/src/server/browserType.ts b/src/server/browserType.ts
index b7a15387c2..3c1c970c47 100644
--- a/src/server/browserType.ts
+++ b/src/server/browserType.ts
@@ -19,6 +19,7 @@ import { TimeoutError } from '../errors';
 import { Browser, ConnectOptions } from '../browser';
 import { BrowserContext } from '../browserContext';
 import { BrowserServer } from './browserServer';
+import { OnProgressCallback } from './browserFetcher';
 
 export type BrowserArgOptions = {
   headless?: boolean,
@@ -44,6 +45,7 @@ export interface BrowserType {
   launchServer(options?: LaunchOptions & { port?: number }): Promise<BrowserServer>;
   launchPersistent(userDataDir: string, options?: LaunchOptions): Promise<BrowserContext>;
   connect(options: ConnectOptions): Promise<Browser>;
+  downloadBrowserIfNeeded(progress?: OnProgressCallback): Promise<void>;
   devices: types.Devices;
   errors: { TimeoutError: typeof TimeoutError };
 }
diff --git a/src/server/chromium.ts b/src/server/chromium.ts
index e987437360..833965f998 100644
--- a/src/server/chromium.ts
+++ b/src/server/chromium.ts
@@ -19,7 +19,7 @@ import * as fs from 'fs';
 import * as os from 'os';
 import * as path from 'path';
 import * as util from 'util';
-import { BrowserFetcher, BrowserFetcherOptions } from '../server/browserFetcher';
+import { BrowserFetcher, OnProgressCallback, BrowserFetcherOptions } from '../server/browserFetcher';
 import { DeviceDescriptors } from '../deviceDescriptors';
 import * as types from '../types';
 import { assert } from '../helper';
@@ -194,6 +194,15 @@ export class Chromium implements BrowserType {
     return chromeArguments;
   }
 
+  async downloadBrowserIfNeeded(onProgress?: OnProgressCallback) {
+    const fetcher = this._createBrowserFetcher();
+    const revisionInfo = fetcher.revisionInfo();
+    // Do nothing if the revision is already downloaded.
+    if (revisionInfo.local)
+      return;
+    await fetcher.download(revisionInfo.revision, onProgress);
+  }
+
   _createBrowserFetcher(options: BrowserFetcherOptions = {}): BrowserFetcher {
     const downloadURLs = {
       linux: '%s/chromium-browser-snapshots/Linux_x64/%d/%s.zip',
diff --git a/src/server/firefox.ts b/src/server/firefox.ts
index a1b6b1ba61..67c0c66810 100644
--- a/src/server/firefox.ts
+++ b/src/server/firefox.ts
@@ -16,7 +16,7 @@
  */
 
 import { FFBrowser } from '../firefox/ffBrowser';
-import { BrowserFetcher, BrowserFetcherOptions } from './browserFetcher';
+import { BrowserFetcher, OnProgressCallback, BrowserFetcherOptions } from './browserFetcher';
 import { DeviceDescriptors } from '../deviceDescriptors';
 import { launchProcess, waitForLine } from './processLauncher';
 import * as types from '../types';
@@ -44,6 +44,15 @@ export class Firefox implements BrowserType {
     this._revision = preferredRevision;
   }
 
+  async downloadBrowserIfNeeded(onProgress?: OnProgressCallback) {
+    const fetcher = this._createBrowserFetcher();
+    const revisionInfo = fetcher.revisionInfo();
+    // Do nothing if the revision is already downloaded.
+    if (revisionInfo.local)
+      return;
+    await fetcher.download(revisionInfo.revision, onProgress);
+  }
+
   name() {
     return 'firefox';
   }
diff --git a/src/server/webkit.ts b/src/server/webkit.ts
index d201e3ec65..9a3297ef3c 100644
--- a/src/server/webkit.ts
+++ b/src/server/webkit.ts
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import { BrowserFetcher, BrowserFetcherOptions } from './browserFetcher';
+import { BrowserFetcher, OnProgressCallback, BrowserFetcherOptions } from './browserFetcher';
 import { DeviceDescriptors } from '../deviceDescriptors';
 import { TimeoutError } from '../errors';
 import * as types from '../types';
@@ -52,6 +52,15 @@ export class WebKit implements BrowserType {
     return 'webkit';
   }
 
+  async downloadBrowserIfNeeded(onProgress?: OnProgressCallback) {
+    const fetcher = this._createBrowserFetcher();
+    const revisionInfo = fetcher.revisionInfo();
+    // Do nothing if the revision is already downloaded.
+    if (revisionInfo.local)
+      return;
+    await fetcher.download(revisionInfo.revision, onProgress);
+  }
+
   async launch(options?: LaunchOptions & { slowMo?: number }): Promise<WKBrowser> {
     const { browserServer, transport } = await this._launchServer(options, 'local');
     const browser = await WKBrowser.connect(transport!, options && options.slowMo);
@@ -84,7 +93,6 @@ export class WebKit implements BrowserType {
       handleSIGINT = true,
       handleSIGTERM = true,
       handleSIGHUP = true,
-      timeout = 30000
     } = options;
 
     let temporaryUserDataDir: string | null = null;
@@ -136,7 +144,6 @@ export class WebKit implements BrowserType {
       },
     });
 
-    const timeoutError = new TimeoutError(`Timed out after ${timeout} ms while trying to connect to WebKit!`);
     transport = new PipeTransport(launchedProcess.stdio[3] as NodeJS.WritableStream, launchedProcess.stdio[4] as NodeJS.ReadableStream);
     browserServer = new BrowserServer(launchedProcess, gracefullyClose, launchType === 'server' ? await wrapTransportWithWebSocket(transport, port || 0) : null);
     return { browserServer, transport };
diff --git a/src/types.ts b/src/types.ts
index 006d077c55..a4de23a5f1 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -27,7 +27,6 @@ export type Evaluate = <Args extends any[], R>(pageFunction: PageFunction<Args,
 export type EvaluateHandle = <Args extends any[], R>(pageFunction: PageFunction<Args,  R>, ...args: Boxed<Args>) => Promise<Handle<R>>;
 export type $Eval = <Args extends any[], R>(selector: string, pageFunction: PageFunctionOn<Element, Args, R>, ...args: Boxed<Args>) => Promise<R>;
 export type $$Eval = <Args extends any[], R>(selector: string, pageFunction: PageFunctionOn<Element[], Args, R>, ...args: Boxed<Args>) => Promise<R>;
-export type $Wait = <Args extends any[], R>(selector: string, pageFunction: PageFunctionOn<Element | undefined, Args, R>, options?: WaitForFunctionOptions, ...args: Boxed<Args>) => Promise<Handle<R>>;
 export type EvaluateOn<T> = <Args extends any[], R>(pageFunction: PageFunctionOn<T, Args, R>, ...args: Boxed<Args>) => Promise<R>;
 export type EvaluateHandleOn<T> = <Args extends any[], R>(pageFunction: PageFunctionOn<T, Args, R>, ...args: Boxed<Args>) => Promise<Handle<R>>;
 
diff --git a/src/webkit/wkBrowser.ts b/src/webkit/wkBrowser.ts
index 659ff0ff76..c17ec2faf0 100644
--- a/src/webkit/wkBrowser.ts
+++ b/src/webkit/wkBrowser.ts
@@ -15,7 +15,7 @@
  * limitations under the License.
  */
 
-import { Browser, collectPages } from '../browser';
+import { Browser, createPageInNewContext } from '../browser';
 import { BrowserContext, BrowserContextOptions } from '../browserContext';
 import { assert, helper, RegisteredListener } from '../helper';
 import * as network from '../network';
@@ -66,6 +66,8 @@ export class WKBrowser extends platform.EventEmitter implements Browser {
   }
 
   _onDisconnect() {
+    for (const context of this.contexts())
+      context._browserClosed();
     for (const pageProxy of this._pageProxies.values())
       pageProxy.dispose();
     this._pageProxies.clear();
@@ -87,13 +89,8 @@ export class WKBrowser extends platform.EventEmitter implements Browser {
     return Array.from(this._contexts.values());
   }
 
-  async pages(): Promise<Page[]> {
-    return collectPages(this);
-  }
-
   async newPage(options?: BrowserContextOptions): Promise<Page> {
-    const context = await this.newContext(options);
-    return context.newPage();
+    return createPageInNewContext(this, options);
   }
 
   async _waitForFirstPageTarget(timeout: number): Promise<void> {
diff --git a/src/webkit/wkPage.ts b/src/webkit/wkPage.ts
index a75e7f5ba6..2b8ee55719 100644
--- a/src/webkit/wkPage.ts
+++ b/src/webkit/wkPage.ts
@@ -545,6 +545,17 @@ export class WKPage implements PageDelegate {
     return { x: minX, y: minY, width: maxX - minX, height: maxY - minY };
   }
 
+  async scrollRectIntoViewIfNeeded(handle: dom.ElementHandle, rect?: types.Rect): Promise<void> {
+    await this._session.send('DOM.scrollIntoViewIfNeeded', {
+      objectId: toRemoteObject(handle).objectId!,
+      rect,
+    }).catch(e => {
+      if (e instanceof Error && e.message.includes('Node does not have a layout object'))
+        e.message = 'Node is either not visible or not an HTMLElement';
+      throw e;
+    });
+  }
+
   async getContentQuads(handle: dom.ElementHandle): Promise<types.Quad[] | null> {
     const result = await this._session.send('DOM.getContentQuads', {
       objectId: toRemoteObject(handle).objectId!
diff --git a/test/browser.spec.js b/test/browser.spec.js
index 4232dce3a8..f5e032ef8e 100644
--- a/test/browser.spec.js
+++ b/test/browser.spec.js
@@ -24,24 +24,26 @@ module.exports.describe = function({testRunner, expect, playwright, CHROMIUM, WE
   const {it, fit, xit, dit} = testRunner;
   const {beforeAll, beforeEach, afterAll, afterEach} = testRunner;
 
-  describe('Browser', function() {
+  describe('Browser.newPage', function() {
     it('should create new page', async function({browser}) {
-      expect((await browser.pages()).length).toBe(0);
       const page1 = await browser.newPage();
-      expect((await browser.pages()).length).toBe(1);
       expect(browser.contexts().length).toBe(1);
 
       const page2 = await browser.newPage();
-      expect((await browser.pages()).length).toBe(2);
       expect(browser.contexts().length).toBe(2);
 
-      await page1.context().close();
-      expect((await browser.pages()).length).toBe(1);
+      await page1.close();
       expect(browser.contexts().length).toBe(1);
 
-      await page2.context().close();
-      expect((await browser.pages()).length).toBe(0);
+      await page2.close();
       expect(browser.contexts().length).toBe(0);
     });
+    it('should throw upon second create new page', async function({browser}) {
+      const page = await browser.newPage();
+      let error;
+      await page.context().newPage().catch(e => error = e);
+      await page.close();
+      expect(error.message).toContain('Please use browser.newContext()');
+    });
   });
 };
diff --git a/test/chromium/chromium.spec.js b/test/chromium/chromium.spec.js
index 5f106e9e1f..6b169fe382 100644
--- a/test/chromium/chromium.spec.js
+++ b/test/chromium/chromium.spec.js
@@ -192,7 +192,7 @@ module.exports.describe = function({testRunner, expect, playwright, FFOX, CHROMI
       await page.goto(server.EMPTY_PAGE);
       const target = await targetPromise;
       expect(await target.page()).toBe(page);
-      await page.close();
+      await page.context().close();
     });
     it('should fire target events', async function({browser, newContext, server}) {
       const context = await newContext();
diff --git a/test/chromium/tracing.spec.js b/test/chromium/tracing.spec.js
index fc9c16309e..d242af429b 100644
--- a/test/chromium/tracing.spec.js
+++ b/test/chromium/tracing.spec.js
@@ -58,7 +58,7 @@ module.exports.describe = function({testRunner, expect, defaultBrowserOptions, p
       const newPage = await browser.newPage();
       let error = null;
       await browser.startTracing(newPage, {path: outputFile}).catch(e => error = e);
-      await newPage.context().close();
+      await newPage.close();
       expect(error).toBeTruthy();
       await browser.stopTracing();
     });
diff --git a/test/click.spec.js b/test/click.spec.js
index f60f5ac365..6b9e4f7f8c 100644
--- a/test/click.spec.js
+++ b/test/click.spec.js
@@ -286,6 +286,8 @@ module.exports.describe = function({testRunner, expect, playwright, FFOX, CHROMI
       expect(await frame.evaluate(() => window.result)).toBe('Clicked');
     });
     // @see https://github.com/GoogleChrome/puppeteer/issues/4110
+    // @see https://bugs.chromium.org/p/chromium/issues/detail?id=986390
+    // @see https://chromium-review.googlesource.com/c/chromium/src/+/1742784
     xit('should click the button with fixed position inside an iframe', async({page, server}) => {
       await page.goto(server.EMPTY_PAGE);
       await page.setViewportSize({width: 500, height: 500});
@@ -326,7 +328,7 @@ module.exports.describe = function({testRunner, expect, playwright, FFOX, CHROMI
       expect(await page.evaluate(() => offsetX)).toBe(WEBKIT ? 12 * 2 + 20 : 20);
       expect(await page.evaluate(() => offsetY)).toBe(WEBKIT ? 12 * 2 + 10 : 10);
     });
-    it('should click a very large button with relative point', async({page, server}) => {
+    it.skip(FFOX)('should click a very large button with relative point', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/button.html');
       await page.$eval('button', button => button.style.borderWidth = '8px');
       await page.$eval('button', button => button.style.height = button.style.width = '2000px');
@@ -336,7 +338,7 @@ module.exports.describe = function({testRunner, expect, playwright, FFOX, CHROMI
       expect(await page.evaluate(() => offsetX)).toBe(WEBKIT ? 1900 + 8 : 1900);
       expect(await page.evaluate(() => offsetY)).toBe(WEBKIT ? 1910 + 8 : 1910);
     });
-    xit('should click a button in scrolling container with relative point', async({page, server}) => {
+    it.skip(FFOX)('should click a button in scrolling container with relative point', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/button.html');
       await page.$eval('button', button => {
         const container = document.createElement('div');
@@ -347,11 +349,13 @@ module.exports.describe = function({testRunner, expect, playwright, FFOX, CHROMI
         container.appendChild(button);
         button.style.height = '2000px';
         button.style.width = '2000px';
+        button.style.borderWidth = '8px';
       });
       await page.click('button', { relativePoint: { x: 1900, y: 1910 } });
       expect(await page.evaluate(() => window.result)).toBe('Clicked');
-      expect(await page.evaluate(() => offsetX)).toBe(1900);
-      expect(await page.evaluate(() => offsetY)).toBe(1910);
+      // Safari reports border-relative offsetX/offsetY.
+      expect(await page.evaluate(() => offsetX)).toBe(WEBKIT ? 1900 + 8 : 1900);
+      expect(await page.evaluate(() => offsetY)).toBe(WEBKIT ? 1910 + 8 : 1910);
     });
 
     it('should update modifiers correctly', async({page, server}) => {
@@ -370,7 +374,7 @@ module.exports.describe = function({testRunner, expect, playwright, FFOX, CHROMI
       await page.click('button');
       expect(await page.evaluate(() => shiftKey)).toBe(false);
     });
-    it.skip(CHROMIUM)('should click an offscreen element when scroll-behavior is smooth', async({page}) => {
+    it('should click an offscreen element when scroll-behavior is smooth', async({page}) => {
       await page.setContent(`
         <div style="border: 1px solid black; height: 500px; overflow: auto; width: 500px; scroll-behavior: smooth">
         <button style="margin-top: 2000px" onClick="window.clicked = true">hi</button>
@@ -379,7 +383,7 @@ module.exports.describe = function({testRunner, expect, playwright, FFOX, CHROMI
       await page.click('button');
       expect(await page.evaluate('window.clicked')).toBe(true);
     });
-    it.skip(true)('should click on an animated button', async({page}) => {
+    xit('should click on an animated button', async({page}) => {
       const buttonSize = 50;
       const containerWidth = 500;
       const transition = 500;
diff --git a/test/elementhandle.spec.js b/test/elementhandle.spec.js
index 65620ba44e..c83d95ad6d 100644
--- a/test/elementhandle.spec.js
+++ b/test/elementhandle.spec.js
@@ -68,6 +68,24 @@ module.exports.describe = function({testRunner, expect, FFOX, CHROMIUM, WEBKIT})
       }, element);
       expect(pwBoundingBox).toEqual(webBoundingBox);
     });
+    it.skip(WEBKIT)('should work with page scale', async({newPage, server}) => {
+      const page = await newPage({ viewport: { width: 400, height: 400, isMobile: true} });
+      await page.goto(server.PREFIX + '/input/button.html');
+      const button = await page.$('button');
+      await button.evaluate(button => {
+        document.body.style.margin = '0';
+        button.style.borderWidth = '0';
+        button.style.width = '200px';
+        button.style.height = '20px';
+        button.style.marginLeft = '17px';
+        button.style.marginTop = '23px';
+      });
+      const box = await button.boundingBox();
+      expect(Math.round(box.x * 100)).toBe(17 * 100);
+      expect(Math.round(box.y * 100)).toBe(23 * 100);
+      expect(Math.round(box.width * 100)).toBe(200 * 100);
+      expect(Math.round(box.height * 100)).toBe(20 * 100);
+    });
   });
 
   describe('ElementHandle.contentFrame', function() {
@@ -201,9 +219,8 @@ module.exports.describe = function({testRunner, expect, FFOX, CHROMIUM, WEBKIT})
     it('should work for TextNodes', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/button.html');
       const buttonTextNode = await page.evaluateHandle(() => document.querySelector('button').firstChild);
-      let error = null;
-      await buttonTextNode.click().catch(err => error = err);
-      expect(error.message).toBe('Node is not of type HTMLElement');
+      await buttonTextNode.click();
+      expect(await page.evaluate(() => result)).toBe('Clicked');
     });
     it('should throw for detached nodes', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/button.html');
@@ -211,7 +228,7 @@ module.exports.describe = function({testRunner, expect, FFOX, CHROMIUM, WEBKIT})
       await page.evaluate(button => button.remove(), button);
       let error = null;
       await button.click().catch(err => error = err);
-      expect(error.message).toBe('Node is detached from document');
+      expect(error.message).toContain('Node is detached from document');
     });
     it('should throw for hidden nodes', async({page, server}) => {
       await page.goto(server.PREFIX + '/input/button.html');
diff --git a/test/jshandle.spec.js b/test/jshandle.spec.js
index 69b72e442d..4506eadd2f 100644
--- a/test/jshandle.spec.js
+++ b/test/jshandle.spec.js
@@ -160,7 +160,7 @@ module.exports.describe = function({testRunner, expect, CHROMIUM, FFOX, WEBKIT})
       const aHandle = await page.evaluateHandle(() => document.querySelector('div').firstChild);
       const element = aHandle.asElement();
       expect(element).toBeTruthy();
-      expect(await page.evaluate(e => e.nodeType === HTMLElement.TEXT_NODE, element));
+      expect(await page.evaluate(e => e.nodeType === HTMLElement.TEXT_NODE, element)).toBeTruthy();
     });
     it('should work with nullified Node', async({page, server}) => {
       await page.setContent('<section>test</section>');
diff --git a/test/launcher.spec.js b/test/launcher.spec.js
index e9685f6ee7..08e87b7518 100644
--- a/test/launcher.spec.js
+++ b/test/launcher.spec.js
@@ -172,6 +172,19 @@ module.exports.describe = function({testRunner, expect, defaultBrowserOptions, p
       expect(error.message).toContain('has been closed');
       await browserServer.close();
     });
+    it('should emit close events on pages and contexts', async({server}) => {
+      const browserServer = await playwright.launchServer({...defaultBrowserOptions });
+      const remote = await playwright.connect({ wsEndpoint: browserServer.wsEndpoint() });
+      const context = await remote.newContext();
+      const page = await context.newPage();
+      let pageClosed = false;
+      page.on('close', e => pageClosed = true);
+      await Promise.all([
+        new Promise(f => context.on('close', f)),
+        browserServer.close()
+      ]);
+      expect(pageClosed).toBeTruthy();
+    });
   });
 
   describe('Browser.close', function() {
diff --git a/test/playwright.spec.js b/test/playwright.spec.js
index 18f4920b57..63aedfebc1 100644
--- a/test/playwright.spec.js
+++ b/test/playwright.spec.js
@@ -118,6 +118,7 @@ module.exports.describe = ({testRunner, product, playwrightPath}) => {
 
       state.tearDown = async () => {
         await Promise.all(contexts.map(c => c.close()));
+        expect((await state.browser.contexts()).length).toBe(0, `"${test.fullName}" leaked a context`);
         if (rl) {
           rl.removeListener('line', onLine);
           rl.close();
diff --git a/test/waittask.spec.js b/test/waittask.spec.js
index 9bb1bead96..0f110840a7 100644
--- a/test/waittask.spec.js
+++ b/test/waittask.spec.js
@@ -208,39 +208,8 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
     });
   });
 
-  describe('Frame.$wait', function() {
-    it('should accept arguments', async({page, server}) => {
-      await page.setContent('<div></div>');
-      const result = await page.$wait('div', (e, foo, bar) => e.nodeName + foo + bar, {}, 'foo1', 'bar2');
-      expect(await result.jsonValue()).toBe('DIVfoo1bar2');
-    });
-    it('should query selector constantly', async({page, server}) => {
-      await page.setContent('<div></div>');
-      let done = null;
-      const resultPromise = page.$wait('span', e => e).then(r => done = r);
-      expect(done).toBe(null);
-      await page.setContent('<section></section>');
-      expect(done).toBe(null);
-      await page.setContent('<span>text</span>');
-      await resultPromise;
-      expect(done).not.toBe(null);
-      expect(await done.evaluate(e => e.textContent)).toBe('text');
-    });
-    it('should be able to wait for removal', async({page}) => {
-      await page.setContent('<div></div>');
-      let done = null;
-      const resultPromise = page.$wait('div', e => !e).then(r => done = r);
-      expect(done).toBe(null);
-      await page.setContent('<section></section>');
-      await resultPromise;
-      expect(done).not.toBe(null);
-      expect(await done.jsonValue()).toBe(true);
-    });
-  });
-
   describe('Frame.waitForSelector', function() {
     const addElement = tag => document.body.appendChild(document.createElement(tag));
-
     it('should immediately resolve promise if node exists', async({page, server}) => {
       await page.goto(server.EMPTY_PAGE);
       const frame = page.mainFrame();
@@ -248,7 +217,6 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
       await frame.evaluate(addElement, 'div');
       await frame.waitForSelector('div');
     });
-
     it('should work with removed MutationObserver', async({page, server}) => {
       await page.evaluate(() => delete window.MutationObserver);
       const [handle] = await Promise.all([
@@ -257,7 +225,6 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
       ]);
       expect(await page.evaluate(x => x.textContent, handle)).toBe('anything');
     });
-
     it('should resolve promise when node is added', async({page, server}) => {
       await page.goto(server.EMPTY_PAGE);
       const frame = page.mainFrame();
@@ -268,7 +235,6 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
       const tagName = await eHandle.getProperty('tagName').then(e => e.jsonValue());
       expect(tagName).toBe('DIV');
     });
-
     it('should work when node is added through innerHTML', async({page, server}) => {
       await page.goto(server.EMPTY_PAGE);
       const watchdog = page.waitForSelector('h3 div');
@@ -276,7 +242,6 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
       await page.evaluate(() => document.querySelector('span').innerHTML = '<h3><div></div></h3>');
       await watchdog;
     });
-
     it('Page.$ waitFor is shortcut for main frame', async({page, server}) => {
       await page.goto(server.EMPTY_PAGE);
       await utils.attachFrame(page, 'frame1', server.EMPTY_PAGE);
@@ -287,7 +252,6 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
       const eHandle = await watchdog;
       expect(await eHandle.ownerFrame()).toBe(page.mainFrame());
     });
-
     it('should run in specified frame', async({page, server}) => {
       await utils.attachFrame(page, 'frame1', server.EMPTY_PAGE);
       await utils.attachFrame(page, 'frame2', server.EMPTY_PAGE);
@@ -299,7 +263,6 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
       const eHandle = await waitForSelectorPromise;
       expect(await eHandle.ownerFrame()).toBe(frame2);
     });
-
     it('should throw when frame is detached', async({page, server}) => {
       await utils.attachFrame(page, 'frame1', server.EMPTY_PAGE);
       const frame = page.frames()[1];
@@ -391,7 +354,6 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
       expect(error).toBeTruthy();
       expect(error.message).toContain('waiting for selector "[hidden] div" failed: timeout');
     });
-
     it('should respond to node attribute mutation', async({page, server}) => {
       let divFound = false;
       const waitForSelector = page.waitForSelector('.zombo').then(() => divFound = true);
@@ -441,6 +403,11 @@ module.exports.describe = function({testRunner, expect, product, playwright, FFO
       const tagName = await eHandle.getProperty('tagName').then(e => e.jsonValue());
       expect(tagName).toBe('SPAN');
     });
+    it('$wait alias should work', async({page, server}) => {
+      await page.setContent('<section>test</section>');
+      const handle = await page.$wait('section');
+      expect(await handle.evaluate(e => e.textContent)).toBe('test');
+    });
   });
 
   describe('Frame.waitForSelector xpath', function() {
diff --git a/test/web.spec.js b/test/web.spec.js
index 8e84de2d5e..d18d2b3cb7 100644
--- a/test/web.spec.js
+++ b/test/web.spec.js
@@ -46,7 +46,7 @@ module.exports.describe = function({testRunner, expect, defaultBrowserOptions, p
 
     afterEach(async state => {
       await state.page.evaluate(() => teardown());
-      await state.page.context().close();
+      await state.page.close();
       state.page = null;
     });