[WVDRM] Fix for stuttering on low bandwidth

Reintroduces the play/pause rebuffering logic we eliminated
in JB zero day to fix double spins and slow startup - but
activates that logic only based on a comparison of the
current bandwidth measurement and the lowest bitrate track
in the movie.

Needs to be submitted with related changes in /frameworks/av

bug: 7230071
Change-Id: Ib3859a961bd3901a9c4df01eeab2b8b75f49aefe

proprietary/wvm/WVMMediaSource.cpp

@@ -37,7 +37,6 @@ WVMMediaSource::WVMMediaSource(WVSession *session, WVEsSelector esSelector,
       mIsLiveStream(isLive),
       mNewSegment(false),
       mCryptoInitialized(false),
-      mIsStalled(false),
       mStripADTS(false),
       mGroup(NULL),
       mKeyTime(0),
@@ -214,8 +213,6 @@ status_t WVMMediaSource::read(MediaBuffer **buffer, const ReadOptions *options)
 {
     Mutex::Autolock autoLock(mLock);
 
-    mIsStalled = false;
-
     CHECK(mStarted);
 
     *buffer = NULL;
@@ -351,8 +348,6 @@ status_t WVMMediaSource::read(MediaBuffer **buffer, const ReadOptions *options)
                 return ERROR_IO;
             } else {
                 // Didn't get anything, sleep a bit so we don't hog the CPU then try again
-                if (retryCount > 10)
-                    mIsStalled = true;
                 usleep(10000);
                 continue;
             }
@@ -364,15 +359,12 @@ status_t WVMMediaSource::read(MediaBuffer **buffer, const ReadOptions *options)
 
         if (seekNextSync && ((mKeyTime < seekTimeUs) || !syncFrame)) {
             // drop frames up to next sync if requested
-            mIsStalled = true;
             usleep(10000);
             mDecryptContext.Initialize(mediaBuf);
             mEncryptedSizes.clear();
             continue;
         }
 
-        mIsStalled = false;
-
         if (offset + bytesRead < mediaBuf->size())
             break;