Allow compositing of hidden layers

Allow compositing of hidden layers

Hidden layers may require compositing in order for animation machinery
to be plumbed to the compositor. This was broken in r170249. With this
CL, we allow hidden layers to be composited, but only if they house a
compositor-driven animation.

BUG=444852
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196451

[Ian Vollick, 2015-06-03 15:51:01]

vollick@chromium.org changed reviewers:
+ dstockwell@chromium.org

[dstockwell, 2015-06-04 01:05:20]

lgtm

[Ian Vollick, 2015-06-04 01:05:49]

The CQ bit was checked by vollick@chromium.org

[commit-bot: I haz the power, 2015-06-04 01:06:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1161093004/40001

[commit-bot: I haz the power, 2015-06-04 01:43:15]

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

[commit-bot: I haz the power, 2015-06-04 01:43:17]

Try jobs failed on following builders:
  linux_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/6...)

[Ian Vollick, 2015-06-04 02:32:21]

The CQ bit was checked by vollick@chromium.org

[commit-bot: I haz the power, 2015-06-04 02:33:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1161093004/40001

[commit-bot: I haz the power, 2015-06-04 03:55:26]

Committed patchset #3 (id:40001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196451