* Move Properties::Init into platform-specific code
This enables a refactor where property initialization for CE CDM will
use values provided by the application during library initialization.
[ Merge of http://go/wvgerrit/14510/ ]
* Add Properties::AlwaysUseKeySetIds().
When true, all sessions will have key set IDs and all session IDs
will be the same as the corresponding key set ID.
This will help the new CDM interface stick more closely to the EME
APIs, in which there are no such things as key set IDs and sessions
only have a single, random ID used for both streaming and offline.
[ Merge of http://go/wvgerrit/14521/ ]
* Reserve key set IDs in memory, rather than on the file system.
This makes it more efficient to use key set IDs for non-offline
sessions.
[ Merge of http://go/wvgerrit/14535/ ]
Change-Id: I765c3519619b17cc3c4ef95b1a6b125f479ee1d0