NuPlayer: pause playback when buffering is low

also fix buffering percentage report (should be the buffered position)

bug: 18730095
Change-Id: I11e7ca4ba9e772a1ae76861ca1ff1725b62f65ae
diff --git a/media/libmediaplayerservice/nuplayer/GenericSource.h b/media/libmediaplayerservice/nuplayer/GenericSource.h
index 1b63a1f..385d73a 100644
--- a/media/libmediaplayerservice/nuplayer/GenericSource.h
+++ b/media/libmediaplayerservice/nuplayer/GenericSource.h
@@ -94,16 +94,17 @@
         kWhatSeek,
         kWhatReadBuffer,
         kWhatStopWidevine,
+        kWhatStart,
+        kWhatResume,
     };
 
-    Vector<sp<MediaSource> > mSources;
-
     struct Track {
         size_t mIndex;
         sp<MediaSource> mSource;
         sp<AnotherPacketSource> mPackets;
     };
 
+    Vector<sp<MediaSource> > mSources;
     Track mAudioTrack;
     int64_t mAudioTimeUs;
     int64_t mAudioLastDequeueTimeUs;
@@ -119,6 +120,7 @@
     bool mAudioIsVorbis;
     bool mIsWidevine;
     bool mIsSecure;
+    bool mIsStreaming;
     bool mUIDValid;
     uid_t mUID;
     sp<IMediaHTTPService> mHTTPService;
@@ -143,6 +145,8 @@
     int64_t mBitrate;
     int32_t mPollBufferingGeneration;
     uint32_t mPendingReadBufferTypes;
+    bool mBuffering;
+    bool mPrepareBuffering;
     mutable Mutex mReadBufferLock;
 
     sp<ALooper> mLooper;
@@ -194,8 +198,13 @@
 
     void schedulePollBuffering();
     void cancelPollBuffering();
+    void restartPollBuffering();
     void onPollBuffering();
     void notifyBufferingUpdate(int percentage);
+    void startBufferingIfNecessary();
+    void stopBufferingIfNecessary();
+    void sendCacheStats();
+    void ensureCacheIsFetching();
 
     DISALLOW_EVIL_CONSTRUCTORS(GenericSource);
 };