MediaStreamRemoteVideoSource: Wrap cricket::VideoFrame instead of copying.

media/base/video_frame.cc

Index: media/base/video_frame.cc
diff --git a/media/base/video_frame.cc b/media/base/video_frame.cc
index c837159958739edb5d4d3708d1dab8af0bc45562..7fb7d5719f1ff6802da7479562a036ffaea468c4 100644
--- a/media/base/video_frame.cc
+++ b/media/base/video_frame.cc
@@ -344,6 +344,29 @@ scoped_refptr<VideoFrame> VideoFrame::WrapExternalYuvData(
   return frame;
 }
 
+// static
+scoped_refptr<VideoFrame> VideoFrame::WrapExternalYuvConstData(
+    Format format,
+    const gfx::Size& coded_size,
+    const gfx::Rect& visible_rect,
+    const gfx::Size& natural_size,
+    int32 y_stride,
+    int32 u_stride,
+    int32 v_stride,
+    const uint8* y_data,
+    const uint8* u_data,
+    const uint8* v_data,
+    base::TimeDelta timestamp,
+    const base::Closure& no_longer_needed_cb) {
+  // Const cast is ok because the pointers will be protected by |is_read_only_|.
+  scoped_refptr<VideoFrame> frame = WrapExternalYuvData(
+      format, coded_size, visible_rect, natural_size, y_stride, u_stride,
+      v_stride, const_cast<uint8*>(y_data), const_cast<uint8*>(u_data),
+      const_cast<uint8*>(v_data), timestamp, no_longer_needed_cb);
+  frame->is_read_only_ = true;
+  return frame;
+}
+
 #if defined(OS_POSIX)
 // static
 scoped_refptr<VideoFrame> VideoFrame::WrapExternalDmabufs(
@@ -671,6 +694,7 @@ VideoFrame::VideoFrame(VideoFrame::Format format,
       coded_size_(coded_size),
       visible_rect_(visible_rect),
       natural_size_(natural_size),
+      is_read_only_(false),
       mailbox_holder_(mailbox_holder.Pass()),
       shared_memory_handle_(base::SharedMemory::NULLHandle()),
       shared_memory_offset_(0),
@@ -746,6 +770,7 @@ const uint8* VideoFrame::data(size_t plane) const {
 
 uint8* VideoFrame::data(size_t plane) {
   DCHECK(IsValidPlane(plane, format_));
+  DCHECK(!is_read_only_);
   return data_[plane];
 }
 
@@ -767,6 +792,7 @@ const uint8* VideoFrame::visible_data(size_t plane) const {
 }
 
 uint8* VideoFrame::visible_data(size_t plane) {
+  DCHECK(!is_read_only_);
   return const_cast<uint8*>(
       static_cast<const VideoFrame*>(this)->visible_data(plane));
 }