Add WebGLSampler support
Reference: https://www.khronos.org/registry/webgl/specs/latest/2.0/#3.7.13
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cc @jdm @zakorgy
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This patch adds initial support for WebGLSync.
Note:
There is no test for the isSync, deleteSync and waitSync functions in the `conformance2/sync/sync-webgl-specific.html`.
There are a few canvas2d-related dependencies that haven't updated, but they
only use euclid internally so that's not blocking landing the rest of the
changes.
Given the size of this patch, I think it's useful to get this landed as-is.
Receive streams in WebRTC (and MediaStreamTrack support)
This adds the `ontrack` event handler to webrtc, and all the `MediaStreamTrack` stuff necessary to make it work.
WebRTC has the ability to group media tracks into streams using MSIDs, but I haven't yet figured out how to do this. For now, `ontrack` should work.
This _should_ be complete, but it hasn't yet been tested (hence the WIP)
r? @ferjm or @jdm
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MediaStream playback through audio and video elements
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