Backout bug 876542 to fix regressions,a=leo+ (from bug 891142)
Bug 890394 - Prevent incorrect state transition. r=doublec, a=leo+
Bug 885349 - Add flag to context menu to detect audio being played in video elements. r=jlebar, a=leo+
Bug 741102 - Ensure fullscreen button is hidden when audio files are loaded. r=jaws, a=leo+
Backed out changeset 777ab5f22878 (bug 741102) for mochitest-5 failures. a=orange
Merge b2g18 to v1.1hd. a=merge