The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9b40551330cff4baae0e3101e00fdbe6cc20ee08

commit 9b40551330cff4baae0e3101e00fdbe6cc20ee08
Author: wutao <wutao@chromium.org>
Date: Tue Nov 28 00:52:45 2017

cros: Use transform animation for Launcher dismiss animation.

Currently Launcher dismiss animation is using SetBounds, which will call
SetBoundsFromAnimation on each OnProgress. This will generate additional
overhead with a whole commit every frame. This cl converts it to use
ThreadedTransformTransition, which will let compositor optimize and
accelerate the animation.

Eve with DCHECK build, improved average smoothness from 84% to 99%.

Bug:  788928 
Test: 
Change-Id: I10a3fcb8c2895d71bf262b30c72b9f67fd0634ea
Reviewed-on: https://chromium-review.googlesource.com/792001
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Tao Wu <wutao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519491}
[modify] https://crrev.com/9b40551330cff4baae0e3101e00fdbe6cc20ee08/ui/app_list/presenter/app_list_presenter_impl.cc