NuPlayer: Fix flush mode decoder error handling

Explicitly handle each flush mode upon decoder error.
Do not clear out affected decoder immediately.
Alter logcat messages for better diagnostics.

Bug: 17638878
Bug: 17679341
Change-Id: I219796c04d65d7c4dd61c0d4f99f9f580241a68b
diff --git a/media/libmediaplayerservice/nuplayer/GenericSource.h b/media/libmediaplayerservice/nuplayer/GenericSource.h
index 24bb6af..1741f27 100644
--- a/media/libmediaplayerservice/nuplayer/GenericSource.h
+++ b/media/libmediaplayerservice/nuplayer/GenericSource.h
@@ -93,6 +93,7 @@
         kWhatSelectTrack,
         kWhatSeek,
         kWhatReadBuffer,
+        kWhatStopWidevine,
     };
 
     Vector<sp<MediaSource> > mSources;
@@ -131,6 +132,7 @@
     DrmManagerClient *mDrmManagerClient;
     sp<DecryptHandle> mDecryptHandle;
     bool mStarted;
+    bool mStopRead;
     String8 mContentType;
     AString mSniffedMIME;
     off64_t mMetaDataSize;