Revert 245445 "Unifies LayerTreeHost::SetNeedsUpdateLayers and S..."

Speculative. This may have caused flakiness on multiple bots. See bug 335582.

> Unifies LayerTreeHost::SetNeedsUpdateLayers and SetNeedsAnimate -- V2
> 
> [2/2] Unifies LayerTreeHost::SetNeedsUpdateLayers and SetNeedsAnimate
> 
> They basically do the same thing except that SetNeedsAnimate makes the next
> commit non-cancellable. However there is really no reason why SetNeedsAnimate
> need to enforce a commit even if no tiles are updated and no layer properties
> changed.
> 
> SetNeedsAnimate is thus merged into SetNeedsUpdateLayers. The proper use of
> it is when there are potential layout/tile changes, we can use it to defer
> calculation until the next frame. A commit will be scheduled but can be
> cancelled if no updates are needed after calculation.
> 
> This part of the patch changes code behavior slightly.
> SingleThreadProxy::SetNeedsUpdateLayers was originally implemented as
> RenderWidget::ScheduleComposite but now it is RenderWidget::ScheduleAnimation.
> ThreadProxy::SetNeedsAnimate was non-cancellable but is now cancellable.
> 
> [1/2] Cleanup RenderWidget::scheduleComposite/scheduleAnimation
> 
> scheduleComposite has been renamed to ScheduleComposite as it is no longer
> a part of WebWidgetClient API.
> 
> scheduleAnimation has been renamed to ScheduleAnimation. The semantics is to
> schedule a composite and also (potentially) animating WebWidget.
> 
> A new WebWidgetClient API scheduleUpdate has been added, to replace the old
> scheduleAnimation. The semantics is to notify the embedder that something in
> the WebWidget may change in 0 seconds. (i.e. it is allowed to be called
> during a redraw, in such case another redraw will be scheduled after frame
> delay.
> 
> This part of the patch should not change code behavior.
> 
> BUG=316929
> R=danakj,jamesr,jochen
> 
> Review URL: https://codereview.chromium.org/133263004

TBR=trchen@chromium.org
BUG=335582

Review URL: https://codereview.chromium.org/141833002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245528 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245528