Support doing CopyOutputRequests on surfaces.

Support doing CopyOutputRequests on surfaces.

If a surface has a copy output request pending, then the aggregator should avoid merging its root pass into its parent pass, and should instead place the copy request on it.

BUG=397730
Committed: https://crrev.com/2cd9f8f5c3acf503ade180a5584a2c5c1e1004e1
Cr-Commit-Position: refs/heads/master@{#294957}

[jbauman, 2014-09-12 20:07:31]

jbauman@chromium.org changed reviewers:
+ jamesr@chromium.org

[jamesr, 2014-09-15 17:30:54]

lgtm

[jbauman, 2014-09-15 23:12:29]

The CQ bit was checked by jbauman@chromium.org

[commit-bot: I haz the power, 2014-09-15 23:32:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/565313003/20001

[commit-bot: I haz the power, 2014-09-16 01:06:41]

Committed patchset #2 (id:20001) as 71b2771306ec03058c61cade1b95ac6167c2ff7a

[commit-bot: I haz the power, 2014-09-16 01:09:20]

Patchset 2 (id:??) landed as
https://crrev.com/2cd9f8f5c3acf503ade180a5584a2c5c1e1004e1
Cr-Commit-Position: refs/heads/master@{#294957}