Fix issue 2553359: Pandora does not work well with Passion deskdock / Cardock.

The problem is due to a too big difference between the buffer size used at the hardware interface and at the A2DP interface.
When no resampling occurs we don't notice problems but the timing is very tight. As soon as resampling is activated, the AudioTrack underruns.
This is because the AudioTrack buffers are not resized when moving the AudioTrack from hardware to A2DP output.
The AudioTrack buffers are calculated based on a hardware output buffer size of 3072 bytes. Which is much less than the A2DP output buffer size (10240).

The solution consists in creating new tracks with new buffers in AudioFlinger when the A2DP output is opened
instead of just transfering active tracks from hardware output mixer thread to the new A2DP output mixer thread.
To avoid synchronization issues between mixer threads and client processes, this is done by invalidating tracks
by setting a flag in their control block and having AudioTrack release the handle on this track (IAudioTrack)
and create a new IAudioTrack when this flag is detected next time obtainBuffer() or start() is executed.

AudioFlinger modifications:
- invalidate the tracks when setStreamOutput() is called
- make sure that notifications of output opening/closing and change of stream type to output mapping are sent synchronously to client process.
This is necessary so that AudioSystem has the new stream to output mapping when the AudioTrack detects the invalidate flag in the client process.
Previously their were sent when the corresponding thread loop was executed.

AudioTrack modifications:
- move frame count calculation and verification from set() to createTrack() so that is is updated every time a new IAudioTrack is created.
- detect track invalidate flag in obtainBuffer() and start() and create a new IAudioTrack.

AudioTrackShared modifications
- group all flags (out, flowControlFlag, forceReady...) into a single bit filed to save space.

Change-Id: I9ac26b6192230627d35084e1449640caaf7d56ee
diff --git a/libs/audioflinger/AudioFlinger.h b/libs/audioflinger/AudioFlinger.h
index c4a5305..f35f38b 100644
--- a/libs/audioflinger/AudioFlinger.h
+++ b/libs/audioflinger/AudioFlinger.h
@@ -342,7 +342,7 @@
         virtual     bool        checkForNewParameters_l() = 0;
         virtual     status_t    setParameters(const String8& keyValuePairs);
         virtual     String8     getParameters(const String8& keys) = 0;
-        virtual     void        audioConfigChanged(int event, int param = 0) = 0;
+        virtual     void        audioConfigChanged_l(int event, int param = 0) = 0;
                     void        sendConfigEvent(int event, int param = 0);
                     void        sendConfigEvent_l(int event, int param = 0);
                     void        processConfigEvents();
@@ -547,7 +547,7 @@
                     void        restore() { if (mSuspended) mSuspended--; }
                     bool        isSuspended() { return (mSuspended != 0); }
         virtual     String8     getParameters(const String8& keys);
-        virtual     void        audioConfigChanged(int event, int param = 0);
+        virtual     void        audioConfigChanged_l(int event, int param = 0);
         virtual     status_t    getRenderPosition(uint32_t *halFrames, uint32_t *dspFrames);
 
         struct  stream_type_t {
@@ -613,11 +613,7 @@
         // Thread virtuals
         virtual     bool        threadLoop();
 
-                    void        getTracks(SortedVector < sp<Track> >& tracks,
-                                      SortedVector < wp<Track> >& activeTracks,
-                                      int streamType);
-                    void        putTracks(SortedVector < sp<Track> >& tracks,
-                                      SortedVector < wp<Track> >& activeTracks);
+                    void        invalidateTracks(int streamType);
         virtual     bool        checkForNewParameters_l();
         virtual     status_t    dumpInternals(int fd, const Vector<String16>& args);
 
@@ -764,7 +760,7 @@
         virtual void        releaseBuffer(AudioBufferProvider::Buffer* buffer);
         virtual bool        checkForNewParameters_l();
         virtual String8     getParameters(const String8& keys);
-        virtual void        audioConfigChanged(int event, int param = 0);
+        virtual void        audioConfigChanged_l(int event, int param = 0);
                 void        readInputParameters();
         virtual unsigned int  getInputFramesLost();