[MEDIA_PIPELINE_TF] Bug update

Per my action item, I checked on the status of the bugs with our comments.
The relevant bugs are:

ID    Summary 
12399  <video> add bytesReceived, downloadTime, and networkWaitTime
metrics 
13625  There is no way to pass audio and video content metadata to the
user agent that is required in some cases for playback.
13359  <track> A way is needed to identify the type of data in a track
element 
13357  <video>: Additional AudioTrack.kind categories are needed to
identify tracks where audio descriptions are premixed with main dialogue.
14492  <video> change event when tracks are removed
 


Since we didn't escalate these bugs and they are in process, it is my
understanding that there is nothing we need to do at the moment. If the
editor has questions at some point, we will need to respond at that time.
Of course you are welcome to make comments before the editor asks
questions.

Thanks,
-Clarke