The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/df8336d8c14172e886bcb2cfb49828e9ab92e33c

commit df8336d8c14172e886bcb2cfb49828e9ab92e33c
Author: junov <junov@chromium.org>
Date: Fri Apr 22 21:30:44 2016

Remove ImageData::dispose()

Now that DOMUint8ClampedArray is always a GarbageCollected type,
ImageData::dispose() does not actually achieve anything useful. Since
The m_data field always becomes unreachable at the same time as its
parent ImageBitmapObject, scoped disposal is pointless.

Since this was the only use of the ScopedDisposal template, we can
remove that too.

BUG= 603934 

Review URL: https://codereview.chromium.org/1889153003

Cr-Commit-Position: refs/heads/master@{#389247}

[modify] https://crrev.com/df8336d8c14172e886bcb2cfb49828e9ab92e33c/third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp
[modify] https://crrev.com/df8336d8c14172e886bcb2cfb49828e9ab92e33c/third_party/WebKit/Source/core/html/ImageData.cpp
[modify] https://crrev.com/df8336d8c14172e886bcb2cfb49828e9ab92e33c/third_party/WebKit/Source/core/html/ImageData.h