GitLab

And wires it up for WindowService on top of Aura. Another option is to
add a function to EnvObserver that is called anytime the mouse
location changes, but it didn't seem worth the extra complexity.

BUG=none
TEST=covered by tests

Change-Id: I83c426935b7c618351f5d5a786b8f9c4fc75fd59
Reviewed-on: https://chromium-review.googlesource.com/1024722
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553200}