Replace the guts of AudioRendererBase with calls to scaling algorithm.

media/base/buffer_queue.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // BufferQueue is a simple Buffer manager that handles requests for data
 // while hiding Buffer boundaries, treating its internal queue of Buffers
 // as a contiguous region.
 //
 // This class is not threadsafe and requires external locking.
 
@@ skipping 21 matching lines @@
   // "consumed" buffers.
   void Consume(size_t bytes_to_be_consumed);
 
   // Tries to copy |bytes| bytes from our data to |dest|. Returns the number
   // of bytes successfully copied.
   size_t Copy(uint8* dest, size_t bytes);
 
   // Enqueues |buffer_in| and adds a reference.
   void Enqueue(Buffer* buffer_in);
 
-  // Returns the timestamp of the first buffer plus |data_offset_| in
-  // microseconds, calculated using the conversion |bytes_to_sec|.
-  base::TimeDelta GetTime(double bytes_to_sec);
+  // Returns the current timestamp, taking into account |data_offset_|.
+  base::TimeDelta GetTime();
 
   // Returns true if the |queue_| is empty.
   bool IsEmpty();
 
   // Returns the number of bytes in the |queue_|.
   size_t SizeInBytes();
 
  private:
   // Queued audio data.
   std::deque< scoped_refptr<Buffer> > queue_;
 
   // Remembers the amount of remaining audio data in the front buffer.
   size_t data_offset_;
 
   // Keeps track of the |queue_| size in bytes.
   size_t size_in_bytes_;
 
+  // Keeps track of the most recent time we've seen in case the |queue_| is
+  // empty when our owner asks what time it is.
+  base::TimeDelta most_recent_time_;
+
   DISALLOW_COPY_AND_ASSIGN(BufferQueue);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_BUFFER_QUEUE_H_