The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2ae7c2317f4f06daeb5201ac7f755db318d27528

commit 2ae7c2317f4f06daeb5201ac7f755db318d27528
Author: Philip Rogers <pdr@chromium.org>
Date: Wed Apr 04 17:01:44 2018

[CI] Make FrameIsScrollableDidChange return false when there's no change

FrameIsScrollableDidChange had a typo and always returned true. This
prevented an early-out in ScrollingCoordinator's
UpdateAfterCompositingChangeIfNeeded from being effective.

This patch should have no web-visible changes and should only improve
performance by making an early-out work.

Bug:  826883 
Change-Id: Ic3bbac06b6cf7e6a1097a42ba43d1dfd35dcb0c6
Reviewed-on: https://chromium-review.googlesource.com/994546
Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548101}
[modify] https://crrev.com/2ae7c2317f4f06daeb5201ac7f755db318d27528/third_party/WebKit/Source/core/frame/LocalFrameView.cpp
[modify] https://crrev.com/2ae7c2317f4f06daeb5201ac7f755db318d27528/third_party/WebKit/Source/core/page/scrolling/ScrollingCoordinatorTest.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6190ed6f0afb6d17dad8d5fd864d762c6ec7f147

commit 6190ed6f0afb6d17dad8d5fd864d762c6ec7f147
Author: Philip Rogers <pdr@chromium.org>
Date: Wed Apr 04 23:17:16 2018

[PE] Add an UMA metric for ScrollingCoordinator updates

This patch adds an UMA metric for the time spent in
ScrollingCoordinator::UpdateAfterCompositingChangeIfNeeded when a
compositing-related change does need an update.

Bug:  826883 
Change-Id: I49949aa286bfc2c3c265b9ba99e2b7cd5a33b90b
Reviewed-on: https://chromium-review.googlesource.com/994541
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548239}
[modify] https://crrev.com/6190ed6f0afb6d17dad8d5fd864d762c6ec7f147/third_party/WebKit/Source/core/page/scrolling/ScrollingCoordinator.cpp
[modify] https://crrev.com/6190ed6f0afb6d17dad8d5fd864d762c6ec7f147/third_party/WebKit/Source/core/page/scrolling/ScrollingCoordinatorTest.cpp
[modify] https://crrev.com/6190ed6f0afb6d17dad8d5fd864d762c6ec7f147/tools/metrics/histograms/histograms.xml