GitLab

This CL fixes the MailboxVideoFrameConverter to let ScopedSharedImage be
owned by the unwrapped DMA-buf VideoFrame (a.k.a. origin_frame in the
code). Note that the mailbox VideoFrame sent to the client has a
reference to the wrapping VideoFrame. Therefore, the new ownership model
ensures that the SharedImage lives at least as long as the mailbox
VideoFrame, even if the MailboxVideoFrameConverter dies in the meantime
(this has been observed to happen when pausing a video then switching to
another tab to play another video and then switching back to the
original tab - see referenced bug for more details).

Note that ScopedSharedImage is changed to be mutable. That's because we
need to handle a case in which the visible rectangle of a VideoFrame
changes and the SharedImage needs to be regenerated.

Bug: 1044890
Test: forced the use of VD in krane and went through scenario in bug.
Change-Id: I4ff20b0b5088a7a202efc98747fdb5e7a9e9d5f4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2119153
Commit-Queue: Andres Calderon Jaramillo <andrescj@chromium.org>
Reviewed-by: Chih-Yu Huang <akahuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#754785}