Modular DRM for MediaPlayer: L3 playback fails at OMX mmap; preparDrm preparing

Bug: 34559906
Bug: 38390836
Bug: 38039230
Bug: 62194380

Test: GTS Tests
Change-Id: I51e2479f745a4c3e271628abdd79efcb97368ec2
diff --git a/media/libmediaplayerservice/nuplayer/GenericSource.h b/media/libmediaplayerservice/nuplayer/GenericSource.h
index b0c6695..4064133 100644
--- a/media/libmediaplayerservice/nuplayer/GenericSource.h
+++ b/media/libmediaplayerservice/nuplayer/GenericSource.h
@@ -222,6 +222,7 @@
     int32_t mFetchTimedTextDataGeneration;
     int64_t mDurationUs;
     bool mAudioIsVorbis;
+    // Secure codec is required.
     bool mIsSecure;
     bool mIsStreaming;
     bool mUIDValid;
@@ -310,7 +311,9 @@
             bool seeking, bool formatChange, media_track_type trackType, Track *track);
 
     // Modular DRM
+    // The source is DRM protected and is prepared for DRM.
     bool mIsDrmProtected;
+    // releaseDrm has been processed.
     bool mIsDrmReleased;
     Vector<String8> mMimes;