Revert of Remove AudioBuffer::set_duration(), instead base on frames.

media/base/audio_buffer.h

Index: media/base/audio_buffer.h
diff --git a/media/base/audio_buffer.h b/media/base/audio_buffer.h
index 4ccd3a8f0f6cd22842321f1e53fc27c22391fb07..5d7ab7f5c6700cd05413a691e07408d43177bc53 100644
--- a/media/base/audio_buffer.h
+++ b/media/base/audio_buffer.h
@@ -34,13 +34,16 @@
   // number of buffers must be equal to |channel_count|. |frame_count| is the
   // number of frames in each buffer. |data| must not be null and |frame_count|
   // must be >= 0.
+  //
+  // TODO(jrummell): Compute duration rather than pass it in.
   static scoped_refptr<AudioBuffer> CopyFrom(SampleFormat sample_format,
                                              ChannelLayout channel_layout,
                                              int channel_count,
                                              int sample_rate,
                                              int frame_count,
                                              const uint8* const* data,
-                                             const base::TimeDelta timestamp);
+                                             const base::TimeDelta timestamp,
+                                             const base::TimeDelta duration);
 
   // Create an AudioBuffer with |frame_count| frames. Buffer is allocated, but
   // not initialized. Timestamp and duration are set to kNoTimestamp().
@@ -56,7 +59,8 @@
       int channel_count,
       int sample_rate,
       int frame_count,
-      const base::TimeDelta timestamp);
+      const base::TimeDelta timestamp,
+      const base::TimeDelta duration);
 
   // Create a AudioBuffer indicating we've reached end of stream.
   // Calling any method other than end_of_stream() on the resulting buffer
@@ -98,6 +102,7 @@
   base::TimeDelta timestamp() const { return timestamp_; }
   base::TimeDelta duration() const { return duration_; }
   void set_timestamp(base::TimeDelta timestamp) { timestamp_ = timestamp; }
+  void set_duration(base::TimeDelta duration) { duration_ = duration; }
 
   // If there's no data in this buffer, it represents end of stream.
   bool end_of_stream() const { return end_of_stream_; }
@@ -121,7 +126,8 @@
               int frame_count,
               bool create_buffer,
               const uint8* const* data,
-              const base::TimeDelta timestamp);
+              const base::TimeDelta timestamp,
+              const base::TimeDelta duration);
 
   virtual ~AudioBuffer();