[Mac] Remove webcam capture output on main thread to OS race.

When doing webcam setup and teardown on a background thread, QTKit
appears to have a race condition around how it posts work to the main
thread.  This posts part of teardown to the main thread to work around
the problem.

BUG=152757
TEST=See bug.


Review URL: https://chromiumcodereview.appspot.com/11094031

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@160986 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed