Bug 1071482 - Factor out EME load/setup code, so it can be reused in other tests more easily. r=edwin
Bug 1071482 - Rename test_encryptedMediaExtensions to test_eme_playback to make it easier to run all eme tests with a wildcard. r=edwin

--HG--
rename : dom/media/test/test_encryptedMediaExtensions.html => dom/media/test/test_eme_playback.html
Bug 1071482 - Make content encrypted via EME inaccessible from JS APIs. r=roc
Bug 1071482 - Break a cycle in TrackBuffer and SourceBufferDecoder's MediaTaskQueue's SharedThreadPool. r=cajbir