MediaCodec refactoring part 1-a: buffers become separate class

MediaCodecBuffer is meant to replace ABuffer and MediaBuffer in
communication between framework components. As the first step, replace
use of ABuffer in MediaCodec with MediaCodecBuffer, and adjust related
classes accordingly.

MediaCodec.getBuffer() and related APIs now returns MediaCodecBuffers;
thus change MediaCodec clients to use MediaCodecBuffer accordingly.

Test: manually tested for key use cases (Camera, YouTube and Play Movies)
Change-Id: Iba7ce131645e75ce5ddbf497fb793ab38b7f245b
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
index fe7f8fa..0bd3aa1 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.h
@@ -25,9 +25,9 @@
 
 namespace android {
 
-struct ABuffer;
 class  AWakeLock;
 struct MediaClock;
+class MediaCodecBuffer;
 struct VideoFrameScheduler;
 
 struct NuPlayer::Renderer : public AHandler {
@@ -46,7 +46,7 @@
 
     void queueBuffer(
             bool audio,
-            const sp<ABuffer> &buffer,
+            const sp<MediaCodecBuffer> &buffer,
             const sp<AMessage> &notifyConsumed);
 
     void queueEOS(bool audio, status_t finalResult);
@@ -125,7 +125,7 @@
     };
 
     struct QueueEntry {
-        sp<ABuffer> mBuffer;
+        sp<MediaCodecBuffer> mBuffer;
         sp<AMessage> mNotifyConsumed;
         size_t mOffset;
         status_t mFinalResult;