Make Internals::mainThreadScrollingReasons work with spv2.

Make Internals::mainThreadScrollingReasons work with spv2.

This patch fixes the main thread scrolling reasons when slimming paint v2 is
enabled by adding a non-ScrollingCoordinator codepath. Unlike ScrollingCoordinator,
slimming paint v2's main thread scrolling reasons are maintained per-scrolling
LayoutObjects, so we have to walk the entire layout tree to calculate the page's
main thread scrolling reasons.

BUG=671838
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

[pdr., 2016-12-07 01:53:19]

Description was changed from

==========
Make Internals::mainThreadScrollingReasons work with spv2.

This patch fixes the main thread scrolling reasons when slimming paint v2 is
enabled by adding a non-ScrollingCoordinator codepath. Unlike
ScrollingCoordinator,
slimming paint v2's main thread scrolling reasons are maintained per-scrolling
LayoutObjects, so we have to walk the entire layout tree to calculate the page's
main thread scrolling reasons.

671838
==========

to

==========
Make Internals::mainThreadScrollingReasons work with spv2.

This patch fixes the main thread scrolling reasons when slimming paint v2 is
enabled by adding a non-ScrollingCoordinator codepath. Unlike
ScrollingCoordinator,
slimming paint v2's main thread scrolling reasons are maintained per-scrolling
LayoutObjects, so we have to walk the entire layout tree to calculate the page's
main thread scrolling reasons.

BUG=671838
==========

[pdr., 2016-12-07 01:53:30]

Description was changed from

==========
Make Internals::mainThreadScrollingReasons work with spv2.

This patch fixes the main thread scrolling reasons when slimming paint v2 is
enabled by adding a non-ScrollingCoordinator codepath. Unlike
ScrollingCoordinator,
slimming paint v2's main thread scrolling reasons are maintained per-scrolling
LayoutObjects, so we have to walk the entire layout tree to calculate the page's
main thread scrolling reasons.

BUG=671838
==========

to

==========
Make Internals::mainThreadScrollingReasons work with spv2.

This patch fixes the main thread scrolling reasons when slimming paint v2 is
enabled by adding a non-ScrollingCoordinator codepath. Unlike
ScrollingCoordinator,
slimming paint v2's main thread scrolling reasons are maintained per-scrolling
LayoutObjects, so we have to walk the entire layout tree to calculate the page's
main thread scrolling reasons.

BUG=671838
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[pdr., 2016-12-07 01:53:34]

The CQ bit was checked by pdr@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-07 01:53:53]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-07 03:55:05]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-12-07 03:55:06]

Dry run: Try jobs failed on following builders:
  linux_layout_tests_slimming_paint_v2 on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)