aw: Improve DeferredGpuCommandService scheduling

aw: Improve DeferredGpuCommandService scheduling

Simple fixes first. First if GPU thread is already executing GL, then
don't schedule and just make sure the GPU flushes before finishing
executing said GL.

Then make sure we don't send repeated and unnecessary RequestDrawGL.

BUG=344087
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=273092

[boliu, 2014-05-27 15:11:42]

PTAL

[no sievers, 2014-05-27 20:12:47]

https://codereview.chromium.org/299363003/diff/1/android_webview/browser/defe...
File android_webview/browser/deferred_gpu_command_service.cc (right):

https://codereview.chromium.org/299363003/diff/1/android_webview/browser/defe...
android_webview/browser/deferred_gpu_command_service.cc:21: void set(bool
boolean);
nit: caps Set()/Get()

https://codereview.chromium.org/299363003/diff/1/android_webview/browser/defe...
android_webview/browser/deferred_gpu_command_service.cc:44:
base::LazyInstance<ThreadSafeBool> g_request_pending =
Does it work pretty much as good if you combine the flags into one
(request_pending) and don't reset it until ~ScopedAllowGL() in order to simplify
things a bit?

It seems like the only difference is that you are in Draw while the child has
not requested a flush yet. But does that really happen?

[boliu, 2014-05-27 20:52:30]

both done

[no sievers, 2014-05-27 20:55:22]

lgtm

[boliu, 2014-05-27 21:08:26]

The CQ bit was checked by boliu@chromium.org

[commit-bot: I haz the power, 2014-05-27 21:09:34]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/boliu@chromium.org/299363003/20001

[commit-bot: I haz the power, 2014-05-28 00:44:47]

Change committed as 273092