Squashed commit of the following:

commit 427e927298449826bb5b98327b0c05957aa051e6
Author: Andreas Huber <andih@google.com>
Date:   Fri Feb 12 10:39:07 2010 -0800

    Fixing a race condition in AwesomePlayer and support for suspend/resume.

commit 96201a04b6657b6bd69ec6100f4de66aebcaa0b4
Author: Andreas Huber <andih@google.com>
Date:   Fri Feb 12 10:36:15 2010 -0800

    Protect MPEG4Source's sanity by properly locking.

related-to-bug: 2231576