The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/18d495442a635a8eb397e0705f1270d0448d47d2

commit 18d495442a635a8eb397e0705f1270d0448d47d2
Author: Sammie Quon <sammiequon@google.com>
Date: Tue Aug 21 18:22:23 2018

splitview: Do not maximize windows when exiting to home launcher.

Instead minimize them. UX has some ideas for a nicer looking animation,
but for M70 this is a good stop gap because it prevents a maximize
animation starting then a minimize animation occuring halfway.

Test: added test and manual
Bug:  874596 
Change-Id: I4a7ddfe31bb76f0d7a636c15baf4be0c04121a46
Reviewed-on: https://chromium-review.googlesource.com/1180075
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584839}
[modify] https://crrev.com/18d495442a635a8eb397e0705f1270d0448d47d2/ash/shelf/app_list_shelf_item_delegate.cc
[modify] https://crrev.com/18d495442a635a8eb397e0705f1270d0448d47d2/ash/wm/splitview/split_view_controller.cc
[modify] https://crrev.com/18d495442a635a8eb397e0705f1270d0448d47d2/ash/wm/splitview/split_view_controller.h
[modify] https://crrev.com/18d495442a635a8eb397e0705f1270d0448d47d2/ash/wm/splitview/split_view_controller_unittest.cc
[modify] https://crrev.com/18d495442a635a8eb397e0705f1270d0448d47d2/ash/wm/tablet_mode/tablet_mode_window_manager.cc

#1 fixes it for now so you dont have a overlapping minimize/maximize animations.

Assign to Ben for future work, or to close if its good enough.