Replace usage of WebVector::isEmpty with WebVector::empty().

content/renderer/media/media_stream_renderer_factory_impl.cc

Index: content/renderer/media/media_stream_renderer_factory_impl.cc
diff --git a/content/renderer/media/media_stream_renderer_factory_impl.cc b/content/renderer/media/media_stream_renderer_factory_impl.cc
index 984acde8790bb0302a221dfa1d883c3039f5eb1e..5c6cc964eddc0e781bcae2ee0e789cbc5950f61b 100644
--- a/content/renderer/media/media_stream_renderer_factory_impl.cc
+++ b/content/renderer/media/media_stream_renderer_factory_impl.cc
@@ -72,7 +72,7 @@ MediaStreamRendererFactoryImpl::GetVideoRenderer(
 
   blink::WebVector<blink::WebMediaStreamTrack> video_tracks;
   web_stream.videoTracks(video_tracks);
-  if (video_tracks.isEmpty() ||
+  if (video_tracks.empty() ||
       !MediaStreamVideoTrack::GetTrack(video_tracks[0])) {
     return NULL;
   }
@@ -91,7 +91,7 @@ MediaStreamRendererFactoryImpl::GetAudioRenderer(
   DCHECK(!web_stream.isNull());
   blink::WebVector<blink::WebMediaStreamTrack> audio_tracks;
   web_stream.audioTracks(audio_tracks);
-  if (audio_tracks.isEmpty())
+  if (audio_tracks.empty())
     return NULL;
 
   DVLOG(1) << "MediaStreamRendererFactoryImpl::GetAudioRenderer stream:"