Reposition the PIP window on work area change.

window.

Bug: 841886
Bug: 883118
Bug: b/115291749
Test: Changing shelf from auto-hide to show always repositions PIP
Test: Added unittests.
Change-Id: I20712f90dcf0cd6fc7291e1126cf7a449421ef10
Reviewed-on: https://chromium-review.googlesource.com/c/1220353
Commit-Queue: Eliot Courtney <edcourtney@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602623}
6 files changed