Relanding 1143663007: VideoFrame: Separate Pixel Format from Storage Type.

media/base/mac/video_frame_mac.cc

 // 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.
 
 #include "media/base/mac/video_frame_mac.h"
 
 #include <algorithm>
 
 #include "media/base/mac/corevideo_glue.h"
 #include "media/base/video_frame.h"
@@ skipping 25 matching lines @@
   if (frame.cv_pixel_buffer()) {
     pixel_buffer.reset(frame.cv_pixel_buffer(), base::scoped_policy::RETAIN);
     return pixel_buffer;
   }
 
   // VideoFrame only supports YUV formats and most of them are 'YVU' ordered,
   // which CVPixelBuffer does not support. This means we effectively can only
   // represent I420 and NV12 frames. In addition, VideoFrame does not carry
   // colorimetric information, so this function assumes standard video range
   // and ITU Rec 709 primaries.
-  VideoFrame::Format video_frame_format = frame.format();
+  const VideoFrame::Format video_frame_format = frame.format();
   OSType cv_format;
   if (video_frame_format == VideoFrame::Format::I420) {
     cv_format = kCVPixelFormatType_420YpCbCr8Planar;
   } else if (video_frame_format == VideoFrame::Format::NV12) {
     cv_format = CoreVideoGlue::kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange;
   } else {
     DLOG(ERROR) << " unsupported frame format: " << video_frame_format;
     return pixel_buffer;
   }
 
@@ skipping 56 matching lines @@
                         kCVImageBufferTransferFunction_ITU_R_709_2,
                         kCVAttachmentMode_ShouldPropagate);
   CVBufferSetAttachment(pixel_buffer, kCVImageBufferYCbCrMatrixKey,
                         kCVImageBufferYCbCrMatrix_ITU_R_709_2,
                         kCVAttachmentMode_ShouldPropagate);
 
   return pixel_buffer;
 }
 
 }  // namespace media