* Move internal non-DASH specific code into the 'media' namespace.
* Remove DASH references from generic stream code.
The documentation is not changed as a follow-up patch will factor out
DASH functionality from StreamVideoSource back into a new
DashVideoSource class.
b/18903621
Change-Id: I78d6e4f2824d4983619f17872828d95655fcfe50
* Create generic stream description classes to represent
Representations, AdaptationSets, and Periods.
* Move generic stream selection logic out of MpdProcessor and
into StreamInfoProcessor.
* Refactor DashVideoSource and DashStream to use the generic
stream description classes.
A follow-up patch is required to re-organize files and namespaces.
b/18903621
b/18948677
Change-Id: I8bbb87ebf0242b31541199d0d1d3c40767c93a29