Revert 276130 "cc: Don't swap throttle BeginMainFrame within dea..."
Appears to be causing hang on Linux in WebRtcBrowserTests/WebRtcBrowserTest.EstablishAudioVideoCallAndVerifyMutingWorks.
http://build.chromium.org/p/chromium.linux/builders/Linux%20Tests/builds/11520/steps/content_browsertests/logs/EstablishAudioVideoCallAndVerifyMutingWorks_1
> cc: Don't swap throttle BeginMainFrame within deadline
>
> This will better reflect behavior prior to the
> OutputSurface+Scheduler refactor and will
> prevent us from skipping BeginMainFrames that
> the scheduler only meant to defer.
>
> BUG=381346
>
> Review URL: https://codereview.chromium.org/
311353003
TBR=brianderson@chromium.org
Review URL: https://codereview.chromium.org/
327963003
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276185 0039d316-1c4b-4281-b951-d872f2087c98