The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ea006b85fe786d88e9f65afb6277b50c36c16c1b

commit ea006b85fe786d88e9f65afb6277b50c36c16c1b
Author: Sammie Quon <sammiequon@google.com>
Date: Tue May 15 00:47:18 2018

overview: Animate window when swiping to close.

Add a slide animation after swipe to close is activated.

Test: manual
Bug:  840590 
Change-Id: I97757ae0cc9c05896ea85c83707e789c0dec483d
Reviewed-on: https://chromium-review.googlesource.com/1058529
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558555}
[modify] https://crrev.com/ea006b85fe786d88e9f65afb6277b50c36c16c1b/ash/wm/overview/overview_window_drag_controller.cc
[modify] https://crrev.com/ea006b85fe786d88e9f65afb6277b50c36c16c1b/ash/wm/overview/window_selector.cc
[modify] https://crrev.com/ea006b85fe786d88e9f65afb6277b50c36c16c1b/ash/wm/overview/window_selector.h
[modify] https://crrev.com/ea006b85fe786d88e9f65afb6277b50c36c16c1b/ash/wm/overview/window_selector_item.cc
[modify] https://crrev.com/ea006b85fe786d88e9f65afb6277b50c36c16c1b/ash/wm/overview/window_selector_item.h