GitLab

This make sure starting a new Picture-in-Picture session from the same
video doesn't crash in Chrome OS.

Bug: 852289
Change-Id: I7f4f5f3bed9999c08ee6576e9fe96e559e92009f
Reviewed-on: https://chromium-review.googlesource.com/1102469
Commit-Queue: François Beaufort <beaufort.francois@gmail.com>
Reviewed-by: apacible <apacible@chromium.org>
Cr-Commit-Position: refs/heads/master@{#568355}