commit 14b918b5e1c3df87e6d509848bce539a8dfef264
author sergeyu <sergeyu@chromium.org> Mon Jan 09 23:10:24 2017
committer Commit bot <commit-bot@chromium.org> Mon Jan 09 23:10:24 2017
tree e5c76101da23cc3d4d730733d22681d8b3b6a38a
parent 82550d783ee6c19b15f4cf1c7872cd18e34df1ea

Fix WebrtcVideoStream to handle failed capture requests.

DesktopCapturer implementations are allowed to fail Capture() requests.
In that case the caller it supposed to retry later. WebrtcVideoStream
wasn't handling this case properly. On Windows the first Capture()
request often fails because it requires desktop process initialization.
WebrtcFrameScheduler, WebrtcVideoEncoder and their implementations were
also updated to accept nullptr frames, to make it possible to top-off
previous frame, while the capturer keeps failing.

Also updated DesktopSessionProxy to return ERROR_TEMPORARY instead of
ERROR_PERMANENT when the desktop process is not connected.

BUG=678712

Review-Url: https://codereview.chromium.org/2616213002
Cr-Commit-Position: refs/heads/master@{#442391}