passing |buffer| by reference in AndroidVideoCapturer::OnIncomingFrame

talk/app/webrtc/androidvideocapturer.h

Index: talk/app/webrtc/androidvideocapturer.h
diff --git a/talk/app/webrtc/androidvideocapturer.h b/talk/app/webrtc/androidvideocapturer.h
index fdc86290bb25119b03758a6b9e754516a4fa7aee..df783bdf6fd4a89086b1fbe6c2b93e90488f28e3 100644
--- a/talk/app/webrtc/androidvideocapturer.h
+++ b/talk/app/webrtc/androidvideocapturer.h
@@ -67,9 +67,10 @@ class AndroidVideoCapturer : public cricket::VideoCapturer {
 
   // Called from JNI when a new frame has been captured.
   // Argument |buffer| is intentionally by value, for use with rtc::Bind.
-  void OnIncomingFrame(rtc::scoped_refptr<webrtc::VideoFrameBuffer> buffer,
-                       int rotation,
-                       int64_t time_stamp);
+  void OnIncomingFrame(
+      const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& buffer,
+      int rotation,
+      int64_t time_stamp);
 
   // Called from JNI to request a new video format.
   void OnOutputFormatRequest(int width, int height, int fps);