GitLab

This reverts commit 0b5ca9b6.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 604473 as the
culprit for flakes in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/flake/flake-culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyQwsSDEZsYWtlQ3VscHJpdCIxY2hyb21pdW0vMGI1Y2E5YjY5NzIwMGVhNTdlMDQyMGJlYjE0N2Y0ZmE4ZmJkMTUzZAw

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.chromiumos/linux-chromeos-dbg/8644

Sample Failed Step: views_mus_unittests

Sample Flaky Test: DesktopWindowTreeHostMusTest.WindowMoveShouldNotTransfersBack

Original change's description:
> Transfer touch events back to the original when the window move ends
> 
> The current behavior makes TransferEventsTo() before the window
> move starts, but don't care at its end. This causes errors like
> crbug.com/900363. But we can't simply transfer back to the original
> window unconditionally since someone (like TabDragController) may
> also want to continue dragging on a window other than the original
> source window.
> 
> This CL introduces a new scoped class to control this; it makes
> TransferEventsTo first, and then invokes TransferEventsTo back
> again at the end, but it skips invoking the second transfer if
> someone else also transfers the touch events on the same window.
> 
> BUG=900363
> TEST=the new test case
> 
> Change-Id: I81792872a13f0e4bb2c88b526c92cf689d656b71
> Reviewed-on: https://chromium-review.googlesource.com/c/1310501
> Commit-Queue: Jun Mukai <mukai@chromium.org>
> Reviewed-by: Scott Violet <sky@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#604473}

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
BUG=900363, 900848

Change-Id: Ie326f3b57b2869b0981beb73344fbb530ca21721
Reviewed-on: https://chromium-review.googlesource.com/c/1312613
Cr-Commit-Position: refs/heads/master@{#604528}