Refactor VideoDenoiser to use a buffer pool, replacing explicit double buffering.

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 96 matching lines @@
                         int crop_width,
                         int crop_height);
 
   // The common case of a center crop, when needed to adjust the
   // aspect ratio without distorting the image.
   void CropAndScaleFrom(const rtc::scoped_refptr<VideoFrameBuffer>& src);
 
   // Scale all of |src| to the size of |this| buffer, with no cropping.
   void ScaleFrom(const rtc::scoped_refptr<VideoFrameBuffer>& src);
 
-  // Create a new buffer with identical strides, and copy the pixel data.
-  static rtc::scoped_refptr<I420Buffer> CopyKeepStride(
-      const rtc::scoped_refptr<VideoFrameBuffer>& buffer);
-
   // Returns a rotated versions of |src|. Native buffers are not
   // supported. The reason this function doesn't return an I420Buffer,
   // is that it returns |src| unchanged in case |rotation| is zero.
   static rtc::scoped_refptr<VideoFrameBuffer> Rotate(
       const rtc::scoped_refptr<VideoFrameBuffer>& src,
       VideoRotation rotation);
 
  protected:
   ~I420Buffer() override;
 
@@ skipping 67 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_