Bug 1867492 [wpt PR 43447] - Reland "Allow createEncodedStreams on PC…

…s without encodedInsertableStreams param", a=testonly

Automatic update from web-platform-tests
Reland "Allow createEncodedStreams on PCs without encodedInsertableStreams param"

Change since previous: Reduce number of frames/packets waited for in
insertable-streams web test and add it to SlowTests. See Patchset
1 -> Patchset 5 diff.

This is a reland of commit e5518aa87b722a83596d1fb2a7506d0ab76f1207

Original change's description:
> Allow createEncodedStreams on PCs without encodedInsertableStreams param
>
> Allow creating Encoded Transforms for any Receivers and Senders, so
> long as createEncodedStreams() is called by JS synchronously after
> sender/receiver creation. This is achieved by setting up a WebRTC
> transform on all transceivers, but "short circuiting" it if JS hasn't
> set up its own transform within an event loop spin of creation. This
> will make the transform just pass frames to be transformed directly back
> without invoking the cost of a thread hop or any JS work.
>
> The existing behaviour (dropping all frames until a JS transform is
> installed) is preserved for PCs created with {encodedInsertableStreams:
> true}.
>
> This implements the algorithm defined in https://www.w3.org/TR/2023/WD-webrtc-encoded-transform-20231012/#stream-creation,
> but for the Chromium createEncodedStreams() method, improving
> conformance incrementally.
>
>
> Bug: 1502781
> Change-Id: Ie36d8ed8f431afa97307030646d3b207bf14cf7a
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5040731
> Commit-Queue: Tony Herre <topricechromium.org>
> Reviewed-by: Guido Urdaneta <guidouchromium.org>
> Reviewed-by: Harald Alvestrand <htachromium.org>
> Cr-Commit-Position: refs/heads/main{#1230611}

Bug: 1502781
Change-Id: I70b366f375e1b6c8e90567f5c994423fd738c8fa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5077034
Reviewed-by: Guido Urdaneta <guidouchromium.org>
Commit-Queue: Tony Herre <topricechromium.org>
Cr-Commit-Position: refs/heads/main{#1231330}

--

wpt-commits: 37fc0710e2fe140241682f4b6ce03d5bb0b39133
wpt-pr: 43447

UltraBlame original commit: 535fb3a55e853c3b2a4e530aeadc66420242275c