During content playback AwesomePlayer (wrapped by StagefrightPlayer)
internally creates either a FileSource or ChromiumHTTPDataSource (both of
them derive from DataSource). The DataSource class in StageFright has a
method named DrmInitialization that can create a DrmManagerClient to
interface with Drm pluging maintained by drmserver.
DrmInitialization is a public method and seems to be designed to allow
external caller to associate the DataSource instance with a particular Drm
plugin. However when a DataSource instance is created by AwesomePlayer the
player never call DataSource's DrmInitialization method. I just wonder what
should be the appropriate way of triggering the call of DrmInitialization
when playback a piece of Drm content using StagefrightPlayer/AwesomePlayer.