Implement scoped_const_refptr template.

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.
  */
 
@@ skipping 182 matching lines @@
 void* I420Buffer::native_handle() const {
   return nullptr;
 }
 
 rtc::scoped_refptr<VideoFrameBuffer> I420Buffer::NativeToI420Buffer() {
   RTC_NOTREACHED();
   return nullptr;
 }
 
 rtc::scoped_refptr<I420Buffer> I420Buffer::Copy(
-    const rtc::scoped_refptr<VideoFrameBuffer>& source) {
+    const rtc::scoped_const_refptr<VideoFrameBuffer>& source) {
   int width = source->width();
   int height = source->height();
   rtc::scoped_refptr<I420Buffer> target = I420Buffer::Create(width, height);
   RTC_CHECK(libyuv::I420Copy(source->DataY(), source->StrideY(),
                              source->DataU(), source->StrideU(),
                              source->DataV(), source->StrideV(),
                              target->MutableDataY(), target->StrideY(),
                              target->MutableDataU(), target->StrideU(),
                              target->MutableDataV(), target->StrideV(),
                              width, height) == 0);
 
   return target;
 }
 
 void I420Buffer::SetToBlack() {
   RTC_CHECK(libyuv::I420Rect(MutableDataY(), StrideY(),
                              MutableDataU(), StrideU(),
                              MutableDataV(), StrideV(),
                              0, 0, width(), height(),
                              0, 128, 128) == 0);
 }
 
 void I420Buffer::CropAndScaleFrom(
-    const rtc::scoped_refptr<VideoFrameBuffer>& src,
+    const rtc::scoped_const_refptr<VideoFrameBuffer>& src,
     int offset_x,
     int offset_y,
     int crop_width,
     int crop_height) {
   RTC_CHECK_LE(crop_width, src->width());
   RTC_CHECK_LE(crop_height, src->height());
   RTC_CHECK_LE(crop_width + offset_x, src->width());
   RTC_CHECK_LE(crop_height + offset_y, src->height());
   RTC_CHECK_GE(offset_x, 0);
   RTC_CHECK_GE(offset_y, 0);
@@ skipping 16 matching lines @@
                               crop_width, crop_height,
                               MutableDataY(), StrideY(),
                               MutableDataU(), StrideU(),
                               MutableDataV(), StrideV(),
                               width(), height(), libyuv::kFilterBox);
 
   RTC_DCHECK_EQ(res, 0);
 }
 
 void I420Buffer::CropAndScaleFrom(
-    const rtc::scoped_refptr<VideoFrameBuffer>& src) {
+    const rtc::scoped_const_refptr<VideoFrameBuffer>& src) {
   const int crop_width =
       std::min(src->width(), width() * src->height() / height());
   const int crop_height =
       std::min(src->height(), height() * src->width() / width());
 
   CropAndScaleFrom(
       src,
       (src->width() - crop_width) / 2, (src->height() - crop_height) / 2,
       crop_width, crop_height);
 }
 
-void I420Buffer::ScaleFrom(const rtc::scoped_refptr<VideoFrameBuffer>& src) {
+void I420Buffer::ScaleFrom(
+    const rtc::scoped_const_refptr<VideoFrameBuffer>& src) {
   CropAndScaleFrom(src, 0, 0, src->width(), src->height());
 }
 
 rtc::scoped_refptr<I420Buffer> I420Buffer::CopyKeepStride(
-    const rtc::scoped_refptr<VideoFrameBuffer>& source) {
+    const rtc::scoped_const_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,
@@ skipping 107 matching lines @@
 void* WrappedI420Buffer::native_handle() const {
   return nullptr;
 }
 
 rtc::scoped_refptr<VideoFrameBuffer> WrappedI420Buffer::NativeToI420Buffer() {
   RTC_NOTREACHED();
   return nullptr;
 }
 
 }  // namespace webrtc