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

webrtc/common_video/video_frame_buffer.cc

 /*
  *  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.
  */
 #include "webrtc/common_video/include/video_frame_buffer.h"
@@ skipping 187 matching lines @@
       src,
       (src->width() - crop_width) / 2, (src->height() - crop_height) / 2,
       crop_width, crop_height);
 }
 
 void I420Buffer::ScaleFrom(const rtc::scoped_refptr<VideoFrameBuffer>& src) {
   CropAndScaleFrom(src, 0, 0, src->width(), src->height());
 }
 
 // static
-rtc::scoped_refptr<I420Buffer> I420Buffer::CopyKeepStride(
-    const rtc::scoped_refptr<VideoFrameBuffer>& source) {
-  int width = source->width();
-  int height = source->height();
-  int stride_y = source->StrideY();
-  int stride_u = source->StrideU();
-  int stride_v = source->StrideV();
-  rtc::scoped_refptr<I420Buffer> target =
-      I420Buffer::Create(width, height, stride_y, stride_u, stride_v);
-  RTC_CHECK(libyuv::I420Copy(source->DataY(), stride_y,
-                             source->DataU(), stride_u,
-                             source->DataV(), stride_v,
-                             target->MutableDataY(), stride_y,
-                             target->MutableDataU(), stride_u,
-                             target->MutableDataV(), stride_v,
-                             width, height) == 0);
-
-  return target;
-}
-
-// static
 rtc::scoped_refptr<VideoFrameBuffer> I420Buffer::Rotate(
     const rtc::scoped_refptr<VideoFrameBuffer>& src,
     VideoRotation rotation) {
   RTC_DCHECK(src->DataY());
   RTC_DCHECK(src->DataU());
   RTC_DCHECK(src->DataV());
 
   if (rotation == webrtc::kVideoRotation_0) {
     return src;
   }
@@ skipping 123 matching lines @@
 void* WrappedI420Buffer::native_handle() const {
   return nullptr;
 }
 
 rtc::scoped_refptr<VideoFrameBuffer> WrappedI420Buffer::NativeToI420Buffer() {
   RTC_NOTREACHED();
   return nullptr;
 }
 
 }  // namespace webrtc