The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cc56dea6e9cdb5b77984ce16d9eed858bb7e9636

commit cc56dea6e9cdb5b77984ce16d9eed858bb7e9636
Author: wutao <wutao@chromium.org>
Date: Tue Oct 10 22:43:59 2017

Defer painting in cross fade animation.

This defers layer painting during maximization (cross fade) animations.
By deferring layer painting, it can reduce the chance that render
surface caching improvement would not provide a performance benefit. If
we repaint each frame then those changes would result in a negative
performance impact instead of a positive one.

Bug:  772173 
Test: Check the paint is deferred and updated at the end of animations.
Change-Id: I00d2cd85e44c21e64304e21f572aeee2804b3e25
Reviewed-on: https://chromium-review.googlesource.com/703932
Reviewed-by: David Reveman <reveman@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Tao Wu <wutao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#507802}
[modify] https://crrev.com/cc56dea6e9cdb5b77984ce16d9eed858bb7e9636/ash/wm/window_animations.cc