Revert 256454 "cc: Allow sending BeginMainFrame before draw or a..."

Speculatively reverting this, which caused Android cc_unittests
crash on LayerTreeHostAnimationTestCancelAnimateCommit.
RunMultiThread_DirectRenderer_MainThreadPaint

BUG=351638

> cc: Allow sending BeginMainFrame before draw or activation
> 
> BeginMainFrame before draw:
> Enabled by default because of concurrency benefits.
> When main thread painting, this will block the main thread from
> finishing the commit until the active tree has been drawn.
> When impl side painting, this does not block the main thread.
> 
> The following flag will disable sending BeginMainFrame to the
> main thread before we draw the previous commit:
> --disable-main-frame-before-draw
> 
> BeginMainFrame before activation:
> Disabled by default because of latency concerns.
> This applies only when impl-side-painting is enabled and will
> cause the main thread to block finishing the commit until the
> pending tree is activated.
> 
> The following flags control whether BeginMainFrame is sent to
> the main thread before or after the previous commit has
> activated:
> --enable-main-frame-before-activation
> --disable-main-frame-before-activation
> 
> BUG=293941
> 
> Review URL: https://codereview.chromium.org/23907006

TBR=brianderson@chromium.org

Review URL: https://codereview.chromium.org/196893002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256480 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256480