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Starred by 4 users

Issue metadata

Status: Fixed
Closed: Nov 2016
EstimatedDays: ----
NextAction: ----
OS: ----
Pri: 2
Type: Bug

Blocked on:
issue 668848

issue 563816

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[OffscreenCanvas] WebGL context loss and restoration event handlers must work in a worker

Project Member Reported by, Oct 12 2016

Issue description

We need to make sure that GPU context losses are handles correctly with offscreen canvases. In particular when in a Worker.  We need to add test coverage for this, and fix it if it does not work


Comment 1 by, Oct 12 2016

Actually, OffscreenCanvas is not even an EventTarget at this time, so it definitely does not work.

Comment 2 by, Oct 12 2016

Summary: [OffscreenCanvas] WebGL context loss and restoration event handlers must work in a worker (was: [OffscreenCanvas] Test, and possibly fix WebGL context loss and restoration in a worker)
Blocking: 563816
Labels: -OffscreenCanvas -Pri-3 OffScreenCanvas Pri-2
I think this is important to, make this block shipping. Raise to Pri-2
Status: Assigned (was: Available)
Project Member

Comment 5 by, Nov 16 2016

The following revision refers to this bug:

commit 8372014fc16a378fc7452164db9b3b89fbd62909
Author: xidachen <>
Date: Wed Nov 16 14:20:08 2016

Make OffscreenCanvas an EventTarget

Right now OffscreenCanvas is not an EventTarget, which means that it
cannot listen to any event such as webgl context lost and restoration.

This CL makes OffscreenCanvas an EventTarget. In order to override the
pure virtual function getExecutionContext in EventTarget, we keep a
Member<ExecutionContext> in OffscreenCanvas.

We also added some layout tests here. In this CL, we only tests webgl
context lost and restoration. The layout tests here should be
upstreamed to khronos group on github later on once the spec for
OffscreenCanvas is landed. Also, notice that the context lost test in
worker verifies that all WebGL's API works in a worker.

Note that the tests we have here is pretty much copied from the webgl's
conformance tests.

BUG= 655270 ,  610759 ,  630515 

Cr-Commit-Position: refs/heads/master@{#432478}


Status: Fixed (was: Assigned)

Comment 7 by, Nov 30 2016

Blockedon: 668848

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