Avoid a possible race between entry deletion and a command, in the event a
renderer was sending out-of-order messages.

BUG=69195
TEST=media

Review URL: http://codereview.chromium.org/6227003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71286 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed