Initial import of mediasource code

ferjm commented 6 years ago

I added a few mock implementations and TODOs in the DOM objects just to make the code build with the new imported files, but I will obviously be filling these blanks in follow up PRs.
MediaSource::Duration() is an example of how some of these TODOs will be solved.
I moved some of the imported code to glue:
- ContainerParser.cpp and TrackBuffersManager.cpp, because I temporarily disabled WebM support, as it requires imported a big chunk of code that I'd like to tackle later.
- MediaSourceDecoder.cpp, because of Bug 1421343.

ferjm commented 6 years ago

r? @cpearce @philn

philn commented 6 years ago

@bors-servo r+

bors-servo commented 6 years ago

:pushpin: Commit 30073de has been approved by philn

bors-servo commented 6 years ago

:hourglass: Testing commit 30073de7cd573f7f304ce0e30200c633863d92ca with merge 20f474652a853f3f2579d41f2db336be7cc78e9c...

bors-servo commented 6 years ago

:sunny: Test successful - status-travis Approved by: philn Pushing 20f474652a853f3f2579d41f2db336be7cc78e9c to master...

servo / gecko-media