Allow resizing for PIP windows.

Bug: b/109716842
Test: Able to free resize PIP windows with Android side patch.
Change-Id: If27051f3edc27cebc5f2e27f78daf8ea2f60f60e
Reviewed-on: https://chromium-review.googlesource.com/1134810
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Commit-Queue: Eliot Courtney <edcourtney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577796}
2 files changed