Fix muted audio when playback rate != 1.0 or 0.0

media/base/seekable_buffer.h

 // Copyright (c) 2012 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.
 
 // SeekableBuffer to support backward and forward seeking in a buffer for
 // reading a media data source.
 //
 // In order to support backward and forward seeking, this class buffers data in
 // both backward and forward directions, the current read position can be reset
 // to anywhere in the buffered data.
@@ skipping 42 matching lines @@
   void Clear();
 
   // Reads a maximum of |size| bytes into |data| from the current read
   // position. Returns the number of bytes read.
   // The current read position will advance by the amount of bytes read. If
   // reading caused backward_bytes() to exceed backward_capacity(), an eviction
   // of the backward buffer will be done internally.
   size_t Read(uint8* data, size_t size);
 
   // Copies up to |size| bytes from current position to |data|. Returns
-  // number of bytes copied. Doesn't advance current position.
+  // number of bytes copied. Doesn't advance current position. Optionally
+  // starts at a |forward_offset| from current position.
   size_t Peek(uint8* data, size_t size);
+  size_t Peek(uint8* data, size_t size, size_t forward_offset);
 
   // Returns pointer to the current chunk of data that is being consumed.
   // If there is no data left in the buffer false is returned, otherwise
   // true is returned and |data| and |size| are updated. The returned
   // |data| value becomes invalid when Read(), Append() or Seek()
   // are called.
   bool GetCurrentChunk(const uint8** data, size_t* size) const;
 
   // Appends |buffer_in| to this buffer. Returns false if forward_bytes() is
   // greater than or equals to forward_capacity(), true otherwise. The data
@@ skipping 55 matching lines @@
 
   // A helper method to evict buffers in the backward direction until backward
   // bytes is within the backward capacity.
   void EvictBackwardBuffers();
 
   // An internal method shared by Read() and SeekForward() that actually does
   // reading. It reads a maximum of |size| bytes into |data|. Returns the number
   // of bytes read. The current read position will be moved forward by the
   // number of bytes read. If |data| is NULL, only the current read position
   // will advance but no data will be copied.
-  size_t InternalRead(uint8* data, size_t size, bool advance_position);
+  size_t InternalRead(
+      uint8* data, size_t size, bool advance_position, size_t forward_offset);
 
   // A helper method that moves the current read position forward by |size|
   // bytes.
   // If the return value is true, the operation completed successfully.
   // If the return value is false, |size| is greater than forward_bytes() and
   // the seek operation failed. The current read position is not updated.
   bool SeekForward(size_t size);
 
   // A helper method that moves the current read position backward by |size|
   // bytes.
@@ skipping 19 matching lines @@
   // Keeps track of the most recent time we've seen in case the |buffers_| is
   // empty when our owner asks what time it is.
   base::TimeDelta current_time_;
 
   DISALLOW_COPY_AND_ASSIGN(SeekableBuffer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_SEEKABLE_BUFFER_H_