am afa07b52: Fix tearing for 720P video playback. Hold 2 decoded video frames instead of 1 so that SF can have more room to complete composition. bug 2309411

Merge commit 'afa07b52460a1c9f88294f14f5a2a259543c88b5' into eclair-mr2

* commit 'afa07b52460a1c9f88294f14f5a2a259543c88b5':
  Fix tearing for 720P video playback.