Hoist compositorDrivenAcceleratedScrollingEnabled check out of scrollParent

Hoist compositorDrivenAcceleratedScrollingEnabled check out of scrollParent

This CL moves the compositorDrivenAcceleratedScrollingEnabled check out of
scrollParent so that it's clearer in the callers that this code only does
something when this setting is enabled.

In compositorDrivenAcceleratedScrollingEnabled, this lets us call
compositorDrivenAcceleratedScrollingEnabled once instead of twice, which is
faster. In a future CL, I'll cache compositorDrivenAcceleratedScrollingEnabled
as a compositing trigger, which will make this code actually go fast.

This CL also reorders a bunch of methods in CompositingReasonFinder.cpp to make
it clearer which of these functions are called during style recalc and which
are call unconditionally on all RenderLayers.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=169992

[esprehn, 2014-03-25 23:19:19]

lgtm

[commit-bot: I haz the power, 2014-03-25 23:19:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/205343009/1

[commit-bot: I haz the power, 2014-03-26 00:20:30]

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

[commit-bot: I haz the power, 2014-03-26 00:20:30]

Try jobs failed on following builders:
  tryserver.blink on win_blink_rel

[abarth-chromium, 2014-03-26 00:24:18]

The CQ bit was checked by abarth@chromium.org

[commit-bot: I haz the power, 2014-03-26 00:24:25]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/205343009/1

[commit-bot: I haz the power, 2014-03-26 00:58:20]

Change committed as 169992