Only 3 CLs in this range change WebKit:

- r500483
- r500485
- r500487

These affect accessibility, EME and garbage collection, respectively. Since these tests don't seem dependent on accessibility or EME, I think we revert the GC change speculatively.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/16a22949c41721a9a8b80aa3a0c801dfb54b6bb8

commit 16a22949c41721a9a8b80aa3a0c801dfb54b6bb8
Author: Matt Giuca <mgiuca@chromium.org>
Date: Fri Sep 08 05:05:40 2017

Revert "BlinkGC: Cleanup heap counters"

This reverts commit 5b47e6de1a5ac9b1b2f14a0f6241eaebe778d8f9.

Reason for revert: Speculative revert for breaking 2 WebKit tests.

Very unsure but it's the only CL that looks relevant in the range.

Original change's description:
> BlinkGC: Cleanup heap counters
> 
> - Remove ThreadState::allocated_object_size_ and marked_object_size_ because they are the same as the values in ThreadHeapStats.
> - Remove atomics from ThreadHeapStats
> 
> Bug: 
> Change-Id: I378a81e5087cd8268853ac4b86206e39db932397
> Reviewed-on: https://chromium-review.googlesource.com/654362
> Reviewed-by: Kentaro Hara <haraken@chromium.org>
> Commit-Queue: Keishi Hattori <keishi@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#500487}

TBR=haraken@chromium.org,keishi@chromium.org

Change-Id: Ief9c32fb5d7af05c444200a2e1ceab721a4d0160
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  763235 
Reviewed-on: https://chromium-review.googlesource.com/656997
Reviewed-by: Matt Giuca <mgiuca@chromium.org>
Commit-Queue: Matt Giuca <mgiuca@chromium.org>
Cr-Commit-Position: refs/heads/master@{#500511}
[modify] https://crrev.com/16a22949c41721a9a8b80aa3a0c801dfb54b6bb8/third_party/WebKit/Source/platform/heap/Heap.cpp
[modify] https://crrev.com/16a22949c41721a9a8b80aa3a0c801dfb54b6bb8/third_party/WebKit/Source/platform/heap/Heap.h
[modify] https://crrev.com/16a22949c41721a9a8b80aa3a0c801dfb54b6bb8/third_party/WebKit/Source/platform/heap/HeapPage.cpp
[modify] https://crrev.com/16a22949c41721a9a8b80aa3a0c801dfb54b6bb8/third_party/WebKit/Source/platform/heap/ThreadState.cpp
[modify] https://crrev.com/16a22949c41721a9a8b80aa3a0c801dfb54b6bb8/third_party/WebKit/Source/platform/heap/ThreadState.h

Sorry if this is wrong. I'll keep an eye on it.

This seems to have done the trick.

https://luci-milo.appspot.com/buildbot/chromium.webkit/WebKit%20Linux%20Trusty%20%28dbg%29/4856

is the first build after my revert landed and it is back to green.

Assigning to keishi@chromium.org to fix and re-land. Thanks!

Technically this is fixed now (but still an issue if this CL re-lands).

Thanks! I will investigate