Do not request vsync on touch if using synchronous compositor

Do not request vsync on touch if using synchronous compositor

Nothing registers for the callback in WasShown if using
synchronous compositor, so this does not change any behavior.
So this is only removing unneeded RequestVSyncUpdate

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=289997

[boliu, 2014-08-15 17:59:33]

PTAL

[aelias_OOO_until_Jul13, 2014-08-15 18:16:23]

Hmm, I don't like unnecessarily forking logic depending on mode booleans.  Could
we check if anyone registered for WasShown instead?

[boliu, 2014-08-15 18:19:55]

On 2014/08/15 18:16:23, aelias wrote:
> Hmm, I don't like unnecessarily forking logic depending on mode booleans. 
Could
> we check if anyone registered for WasShown instead?

How about using observing_root_window_?

All the littered usage of using_synchronous_compositor_ probably should be
cleaned up a bit, maybe a follow up later.

[aelias_OOO_until_Jul13, 2014-08-15 18:26:39]

lgtm

[boliu, 2014-08-15 18:26:59]

The CQ bit was checked by boliu@chromium.org

[commit-bot: I haz the power, 2014-08-15 18:32:30]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/boliu@chromium.org/476233002/20001

[commit-bot: I haz the power, 2014-08-15 20:25:19]

Committed patchset #2 (20001) as 289997