Make scrollbars in pinch viewport invisible until compositor makes them visible.

Make scrollbars in pinch viewport invisible until compositor makes them visible.

This will prevent the pinch viewport overlay scrollbars from showing up
in layout tests. Does not change visibility in normal browser usage.

BUG=148816
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184669

[bokan, 2014-10-30 14:17:16]

bokan@chromium.org changed reviewers:
+ aelias@chromium.org

[bokan, 2014-10-30 14:17:26]

Does this look ok?

[aelias_OOO_until_Jul13, 2014-10-30 18:35:06]

aelias@chromium.org changed reviewers:
+ rbyers@chromium.org

[aelias_OOO_until_Jul13, 2014-10-30 18:35:20]

lgtm, adding rbyers@ for Source/core OWNERS

[gmorrita, 2014-10-30 18:48:46]

morrita@google.com changed reviewers:
+ morrita@google.com

[gmorrita, 2014-10-30 18:48:47]

rubberstamping LGTM for making bot green.
Some audits from experts are desirable.

https://codereview.chromium.org/689543004/diff/1/Source/core/frame/PinchViewp...
File Source/core/frame/PinchViewport.cpp (right):

https://codereview.chromium.org/689543004/diff/1/Source/core/frame/PinchViewp...
Source/core/frame/PinchViewport.cpp:314:
webScrollbarLayer->layer()->setOpacity(0);
Apparently having some API on WebScrollbarLayer looks better than touching
layer() directly?

[bokan, 2014-10-30 18:52:25]

The CQ bit was checked by bokan@chromium.org

[commit-bot: I haz the power, 2014-10-30 18:53:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/689543004/1

[commit-bot: I haz the power, 2014-10-30 19:00:21]

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

[commit-bot: I haz the power, 2014-10-30 19:00:22]

Try jobs failed on following builders:
  blink_presubmit on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/blink_presubmit/builds/1...)

[Hajime Morrita, 2014-10-30 19:39:11]

Oops. lgtm from the right account :-/

[Hajime Morrita, 2014-10-30 19:39:14]

The CQ bit was checked by morrita@chromium.org

[commit-bot: I haz the power, 2014-10-30 19:39:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/689543004/1

[commit-bot: I haz the power, 2014-10-30 20:46:30]

Committed patchset #1 (id:1) as 184669

[Rick Byers, 2014-10-30 21:38:55]

Sorry for the delay, LGTM