Add trace around color conversion (VideoCaptureController::OnIncomingCapturedFrame).

content/browser/renderer_host/media/video_capture_controller.cc

Index: content/browser/renderer_host/media/video_capture_controller.cc
diff --git a/content/browser/renderer_host/media/video_capture_controller.cc b/content/browser/renderer_host/media/video_capture_controller.cc
index 3efc4ce26edf02b563027172c47cd4104634d7d0..a9c11a6291c9c3bf17a5aa3162627746b3eb4c6f 100644
--- a/content/browser/renderer_host/media/video_capture_controller.cc
+++ b/content/browser/renderer_host/media/video_capture_controller.cc
@@ -7,6 +7,7 @@
 #include <set>
 
 #include "base/bind.h"
+#include "base/debug/trace_event.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
@@ -268,6 +269,8 @@ void VideoCaptureController::OnIncomingCapturedFrame(
          frame_info_.color == media::VideoCaptureCapability::kYV12 ||
          (rotation == 0 && !flip_vert && !flip_horiz));
 
+  TRACE_EVENT0("video", "VideoCaptureController::OnIncomingCapturedFrame");
+
   scoped_refptr<media::VideoFrame> dst;
   {
     base::AutoLock lock(buffer_pool_lock_);