The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3b88daf0122e898c95e1a58d6b7b3abb59302805

commit 3b88daf0122e898c95e1a58d6b7b3abb59302805
Author: Justin Novosad <junov@chromium.org>
Date: Fri Sep 29 16:24:54 2017

Fix defective sync token logic in OffscreenCanvasResourceProvider

When resource type is an AcceleratedStaticBitmapImage, the
WaitSyncTokenCHROMIUM call in the release callback is skipped because the
context_provider_wrapper_ is null. This change fixes the problem by setting
the context_provider_wrapper_ field of the frame resource to the same context
that own the image resource.

BUG= 769161 

Change-Id: Ib05a0fa5a6a0d4dab676fcc27820d1171260a25d
Reviewed-on: https://chromium-review.googlesource.com/685380
Reviewed-by: Olivia Lai <xlai@chromium.org>
Commit-Queue: Justin Novosad <junov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505388}
[modify] https://crrev.com/3b88daf0122e898c95e1a58d6b7b3abb59302805/third_party/WebKit/Source/platform/graphics/OffscreenCanvasResourceProvider.cpp