[Picture-in-Picture] Do not pause playback when exiting from API.

This CL makes sure that PiP video is paused only when user interacts
with the PiP window. If it comes from the API, video should NOT pause.

Bug: 848270, 806249
Change-Id: Id09dffce15ff4b99c24dd53696f5715d76937f9e
Reviewed-on: https://chromium-review.googlesource.com/1082274
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: François Beaufort <beaufort.francois@gmail.com>
Cr-Commit-Position: refs/heads/master@{#564496}
7 files changed