cc: Remove safe_to_expect_begin_frame workaround

cc: Remove safe_to_expect_begin_frame workaround

The safe_to_expect_begin_frame workaround should no longer be needed
because the scheduler properly only requests a BeginFrame when there
is an output surface now.

Removing the workaround will also help avoid race conditions where
we receive overlapping BeginFrames with the deadline scheduler.

BUG=289627
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=222729

[brianderson, 2013-09-11 19:06:51]

Adding @reveman as a reviewer since this removes a workaround for a bug that we
both landed fixes for before.

[nduca, 2013-09-11 22:50:50]

lgtm if it helps

[commit-bot: I haz the power, 2013-09-11 22:54:11]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/brianderson@chromium.org/24019008/1

[commit-bot: I haz the power, 2013-09-12 02:01:21]

Commit queue rejected this change because the description was changed
between the time the change entered the commit queue and the time it
was ready to commit. You can safely check the commit box again.

[commit-bot: I haz the power, 2013-09-12 02:11:08]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/brianderson@chromium.org/24019008/1

[commit-bot: I haz the power, 2013-09-12 06:10:46]

Change committed as 222729