Clean up code to use VideoFrameMetadata::MergeMetadataFrom() when appropriate.

content/renderer/media/media_stream_video_capturer_source_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/media_stream_video_capturer_source.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 333 matching lines @@
   }
 
   void DisconnectFromTrack() {
     MediaStreamVideoSink::DisconnectFromTrack();
   }
 
   void OnVideoFrame(const scoped_refptr<media::VideoFrame>& frame,
                     base::TimeTicks capture_time) {
     *capture_time_ = capture_time;
     metadata_->Clear();
-    base::DictionaryValue tmp;
-    frame->metadata()->MergeInternalValuesInto(&tmp);
-    metadata_->MergeInternalValuesFrom(tmp);
+    metadata_->MergeMetadataFrom(frame->metadata());
     base::ResetAndReturn(&got_frame_cb_).Run();
   }
 
  private:
   base::TimeTicks* const capture_time_;
   media::VideoFrameMetadata* const metadata_;
   base::Closure got_frame_cb_;
 };
 
 TEST_F(MediaStreamVideoCapturerSourceTest, CaptureTimeAndMetadataPlumbing) {
@@ skipping 31 matching lines @@
   run_loop.Run();
   fake_sink.DisconnectFromTrack();
   EXPECT_EQ(reference_capture_time, capture_time);
   double metadata_value;
   EXPECT_TRUE(metadata.GetDouble(media::VideoFrameMetadata::FRAME_RATE,
                                  &metadata_value));
   EXPECT_EQ(30.0, metadata_value);
 }
 
 }  // namespace content