Remove implicit conversions from scoped_refptr to T* in content/renderer/media/webrtc*

content/renderer/media/webrtc/video_destination_handler.cc

Index: content/renderer/media/webrtc/video_destination_handler.cc
diff --git a/content/renderer/media/webrtc/video_destination_handler.cc b/content/renderer/media/webrtc/video_destination_handler.cc
index 240f5cd4ea0aa9605b92d188188965f469989d0b..f9b1e03ef344c724955d5d998acc05fb0375fc5e 100644
--- a/content/renderer/media/webrtc/video_destination_handler.cc
+++ b/content/renderer/media/webrtc/video_destination_handler.cc
@@ -97,7 +97,7 @@ void PpFrameWriter::StartSourceImpl(
     const media::VideoCaptureParams& params,
     const VideoCaptureDeliverFrameCB& frame_callback) {
   DCHECK(CalledOnValidThread());
-  DCHECK(!delegate_);
+  DCHECK(!delegate_.get());
   DVLOG(3) << "PpFrameWriter::StartSourceImpl()";
   delegate_ = new FrameWriterDelegate(io_message_loop(), frame_callback);
   OnStartDone(MEDIA_DEVICE_OK);