This is a speculative fix that moves "background pages cleanup"
to `_didCloseInternal` so that it is only run once, but on both
context closure and browser closure.
Symptom from a flaky test:
```log
browserContext.close: page@18087c372d32819222707ca5e8fd1030 is sending "close" event after being disposed
at PageDispatcher._dispatchEvent (D:\a\playwright\playwright\src\dispatchers\dispatcher.ts:86:15)
at Page.<anonymous> (D:\a\playwright\playwright\src\dispatchers\pageDispatcher.ts:59:12)
at Page.emit (events.js:314:20)
at Page._didClose (D:\a\playwright\playwright\src\server\page.ts:220:10)
at CRPage.didClose (D:\a\playwright\playwright\src\server\chromium\crPage.ts:165:16)
at CRBrowserContext._onClosePersistent (D:\a\playwright\playwright\src\server\chromium\crBrowser.ts:476:24)
at CRBrowserContext.close (D:\a\playwright\playwright\src\server\browserContext.ts:288:20)
```
When new page turns into download, we can have `_markAsError` followed
by the `Page.ready` signal and report the page twice (as an error and
as a real page). This is flaky and depends on whether `Page.ready` is
fast enough before the page closes or not.
Exposed by the "should report new window downloads" test.
This patch:
- rolls Firefox to v1269 which is now a firefox-stable build.
- introduces a new channel, `firefox-beta`, for our internal needs.
Fixes#6817
This reverts commit a25b11659be8887b700311180fcd3653aa9e472b.
In a discussion with Dmitry Gozman we decided to revert this and instead
proceed with the following approach:
- rename `//browser_patches/firefox` to `//browser_patches/firefox-beta`
- rename `//browser_patches/firefox-stable` folder to
`//browser_patches/firefox`
In all of the folders, we will keep the `BUILD_NUMBER` original so that
it doesn't clash on the CDN.
This patch:
- starts downloading Firefox Stable equivalent by default
- starts running Firefox-Stable on our smoke tests (tests-1)
- starts running Firefox-Beta on our CQ1 tests (tests-2)
Note: there's a little confusion right now with browser names:
- `firefox-stable` - firefox-stable equivalent
- `firefox`- firefox-beta equivalent
I'll rename `firefox` to `firefox-beta` in a follow-up.
Fixes#6817
