Bug 1044498 - Handle overlapped SourceBuffer appends by spinning up a new decoder.  Only implemented for WebM so far.
Bug 1055967 - Log "discarding video frame" message only when we discard frames.
Bug 1055967 - Fix logging in AudioSink.
Bug 1056452 - Make MediaSource::GetBuffered slightly clearer w.r.t the spec.

Catch null task queue with early assert.

SubBufferDecoder can hold an AbstractMediaDecoder if NotifyDataArrived is added to the interface.  This saves passing "this" to MediaSourceReader::CreateSubDecoder.

Improve logging of TimeRanges.
Bug 1056455 - Move ResourceQueue to a separate header.
Bug 1056534 - Add logging to stubbed out member functions to speed up debugging.
Bug 1056537 - Move MediaDecoderReader::FindStartTime down to only remaining user, OggReader.