Replace size_t with int in a few media classes.

media/base/buffers.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.
 
 // Defines various types of timestamped media buffers used for transporting
 // data between filters.  Every buffer contains a timestamp in microseconds
 // describing the relative position of the buffer within the media stream, and
 // the duration in microseconds for the length of time the buffer will be
 // rendered.
 //
@@ skipping 74 matching lines @@
  private:
   DISALLOW_COPY_AND_ASSIGN(StreamSample);
 };
 
 class MEDIA_EXPORT Buffer : public StreamSample {
  public:
   // Returns a read only pointer to the buffer data.
   virtual const uint8* GetData() const = 0;
 
   // Returns the size of valid data in bytes.
-  virtual size_t GetDataSize() const = 0;
+  virtual int GetDataSize() const = 0;
 
   // If there's no data in this buffer, it represents end of stream.
   virtual bool IsEndOfStream() const OVERRIDE;
 
   // Return DecryptConfig if buffer is encrypted, or NULL otherwise.
   virtual const DecryptConfig* GetDecryptConfig() const;
 
  protected:
   virtual ~Buffer() {}
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_BUFFERS_H_