Revert of Move MutableDataY{,U,V} methods to I420Buffer only.

webrtc/common_video/include/video_frame_buffer.h

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 27 matching lines @@
   // subsampled, this is the highest-resolution plane.
   virtual int width() const = 0;
   virtual int height() const = 0;
 
   // Returns pointer to the pixel data for a given plane. The memory is owned by
   // the VideoFrameBuffer object and must not be freed by the caller.
   virtual const uint8_t* DataY() const = 0;
   virtual const uint8_t* DataU() const = 0;
   virtual const uint8_t* DataV() const = 0;
 
+  // TODO(nisse): Move MutableData methods to the I420Buffer subclass.
+  // Non-const data access.
+  virtual uint8_t* MutableDataY();
+  virtual uint8_t* MutableDataU();
+  virtual uint8_t* MutableDataV();
+
   // Returns the number of bytes between successive rows for a given plane.
   virtual int StrideY() const = 0;
   virtual int StrideU() const = 0;
   virtual int StrideV() const = 0;
 
   // Return the handle of the underlying video frame. This is used when the
   // frame is backed by a texture.
   virtual void* native_handle() const = 0;
 
   // Returns a new memory-backed frame buffer converted from this buffer's
@@ skipping 27 matching lines @@
 
   // Sets the frame buffer to all black.
   void SetToBlack();
 
   int width() const override;
   int height() const override;
   const uint8_t* DataY() const override;
   const uint8_t* DataU() const override;
   const uint8_t* DataV() const override;
 
-  uint8_t* MutableDataY();
-  uint8_t* MutableDataU();
-  uint8_t* MutableDataV();
+  uint8_t* MutableDataY() override;
+  uint8_t* MutableDataU() override;
+  uint8_t* MutableDataV() override;
   int StrideY() const override;
   int StrideU() const override;
   int StrideV() const override;
 
   void* native_handle() const override;
   rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;
 
   // Create a new buffer and copy the pixel data.
   static rtc::scoped_refptr<I420Buffer> Copy(
       const rtc::scoped_refptr<VideoFrameBuffer>& buffer);
@@ skipping 97 matching lines @@
   const uint8_t* const v_plane_;
   const int y_stride_;
   const int u_stride_;
   const int v_stride_;
   rtc::Callback0<void> no_longer_used_cb_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_H_