Update I420Buffer to new VideoFrameBuffer interface

webrtc/test/video_capturer.cc

Index: webrtc/test/video_capturer.cc
diff --git a/webrtc/test/video_capturer.cc b/webrtc/test/video_capturer.cc
index c8b38261cefe182d058187d085c2b9bf78da6c17..d0b5c37becde9f9217976fa78e5475fc1f782160 100644
--- a/webrtc/test/video_capturer.cc
+++ b/webrtc/test/video_capturer.cc
@@ -37,7 +37,7 @@ rtc::Optional<VideoFrame> VideoCapturer::AdaptFrame(const VideoFrame& frame) {
     // return scaled version.
     rtc::scoped_refptr<I420Buffer> scaled_buffer =
         I420Buffer::Create(out_width, out_height);
-    scaled_buffer->ScaleFrom(*frame.video_frame_buffer().get());
+    scaled_buffer->ScaleFrom(*frame.video_frame_buffer()->ToI420());
     out_frame.emplace(
         VideoFrame(scaled_buffer, kVideoRotation_0, frame.timestamp_us()));
   } else {