Bug 1065215 - MSE endOfStream() called within an 'updateend' event can fail with 'object no longer usable' - r=karl
Reopens the MediaSource when SourceBuffer::Remove is called on an Ended
MediaSource. Only run the Range Removal algorithm when MediaSource
duration is changed instead of calling Remove on SourceBuffers.
Updates tests for the fact that update{start,end} can now be called more than once due to DurationChange.
Bug 1065215 - Fix EME test for changes to MediaSource::endOfStream - r=cpearce