Fix incorrect includes of AudioTrack.h

Remove unnecessary includes of AudioTrack.h.
Use forward declaration of class names in preference to #include when possible.

Change-Id: I12982811fa75c2c7695d8bbfa595a7aaec047dc0
diff --git a/include/media/AudioRecord.h b/include/media/AudioRecord.h
index 84a8f1c..44925f2 100644
--- a/include/media/AudioRecord.h
+++ b/include/media/AudioRecord.h
@@ -22,7 +22,6 @@
 
 #include <media/IAudioFlinger.h>
 #include <media/IAudioRecord.h>
-#include <media/AudioTrack.h>
 
 #include <utils/RefBase.h>
 #include <utils/Errors.h>
@@ -34,6 +33,8 @@
 
 namespace android {
 
+class audio_track_cblk_t;
+
 // ----------------------------------------------------------------------------
 
 class AudioRecord
diff --git a/media/libmedia/mediaplayer.cpp b/media/libmedia/mediaplayer.cpp
index acf97a6..f1c47dd 100644
--- a/media/libmedia/mediaplayer.cpp
+++ b/media/libmedia/mediaplayer.cpp
@@ -30,7 +30,7 @@
 #include <gui/SurfaceTextureClient.h>
 
 #include <media/mediaplayer.h>
-#include <media/AudioTrack.h>
+#include <media/AudioSystem.h>
 
 #include <surfaceflinger/Surface.h>
 
diff --git a/media/libmediaplayerservice/MediaPlayerService.h b/media/libmediaplayerservice/MediaPlayerService.h
index 6b68b87..fa71d11 100644
--- a/media/libmediaplayerservice/MediaPlayerService.h
+++ b/media/libmediaplayerservice/MediaPlayerService.h
@@ -34,6 +34,7 @@
 
 namespace android {
 
+class AudioTrack;
 class IMediaRecorder;
 class IMediaMetadataRetriever;
 class IOMX;
diff --git a/media/libmediaplayerservice/MediaRecorderClient.cpp b/media/libmediaplayerservice/MediaRecorderClient.cpp
index d219fc2..beda945 100644
--- a/media/libmediaplayerservice/MediaRecorderClient.cpp
+++ b/media/libmediaplayerservice/MediaRecorderClient.cpp
@@ -33,8 +33,6 @@
 
 #include <utils/String16.h>
 
-#include <media/AudioTrack.h>
-
 #include <system/audio.h>
 
 #include "MediaRecorderClient.h"
diff --git a/media/libmediaplayerservice/MidiFile.h b/media/libmediaplayerservice/MidiFile.h
index dfe4318..f6f8f7b 100644
--- a/media/libmediaplayerservice/MidiFile.h
+++ b/media/libmediaplayerservice/MidiFile.h
@@ -19,7 +19,6 @@
 #define ANDROID_MIDIFILE_H
 
 #include <media/MediaPlayerInterface.h>
-#include <media/AudioTrack.h>
 #include <libsonivox/eas.h>
 
 namespace android {