Add AAC codec specific data for MSE on android

media/mp4/aac.h

Index: media/mp4/aac.h
diff --git a/media/mp4/aac.h b/media/mp4/aac.h
index 2d4b6f45416d243ee853b169651e129b0a361611..331432545874199cd44be6d3e94ec7eace0652ed 100644
--- a/media/mp4/aac.h
+++ b/media/mp4/aac.h
@@ -52,6 +52,16 @@ class MEDIA_EXPORT AAC {
   // unchanged.
   bool ConvertEsdsToADTS(std::vector<uint8>* buffer) const;
 
+#if defined(OS_ANDROID)
+  // Returns the codec specific data needed by android MediaCodec.
+  // The codec specific data contains 2 bytes in the format of:
+  // oooo offf fccc c000
+  // o - audioObjectType
+  // f - samplingFreqIndex
+  // c - channelConfig
+  std::vector<uint8> GetCodecSpecificData() const;
+#endif
+
   // Size in bytes of the ADTS header added by ConvertEsdsToADTS().
   static const size_t kADTSHeaderSize = 7;