The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f56c83740d42e9694104173fde98bc9f23794e2b

commit f56c83740d42e9694104173fde98bc9f23794e2b
Author: Reza.Zakerinasab <zakerinasab@chromium.org>
Date: Mon Aug 21 19:46:59 2017

HTMLCanvasElement::UpdateExternallyAllocatedMemory() should consider color space

HTMLCanvasElement::UpdateExternallyAllocatedMemory() assumes four bytes per pixel.
This change fixes this function to consider color space of the HTMLCanvasElement.

Bug:  756129 
Change-Id: Ia01498971628fae939ec4fef08d8d2b3d45eedb2
Reviewed-on: https://chromium-review.googlesource.com/617513
Reviewed-by: Xida Chen <xidachen@chromium.org>
Reviewed-by: Justin Novosad <junov@chromium.org>
Commit-Queue: Justin Novosad <junov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#496029}
[modify] https://crrev.com/f56c83740d42e9694104173fde98bc9f23794e2b/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp