Bug 804875 - Reset media element when loading a new src. r=kinetik
Bug 804875 - Tests. r=kinetik
Bug 814308 - MediaDecoder::SetDuration doesn't handle aDuration=inf correctly.  r=kinetik
Bug 819377 - Don't offset the clock by the start time of the video in AdvanceFrame, and set the media as playing earlier. r=kinetik