Change TypeConverter<X,Y>::ConvertFrom and ConvertTo into a single symmetric

mojo/services/html_viewer/html_document_view.cc

Index: mojo/services/html_viewer/html_document_view.cc
diff --git a/mojo/services/html_viewer/html_document_view.cc b/mojo/services/html_viewer/html_document_view.cc
index f7a08cb957799285f06d90b253102fc78b5bf8d0..3408c3555eab8f867cf4d3103719904db7e18b63 100644
--- a/mojo/services/html_viewer/html_document_view.cc
+++ b/mojo/services/html_viewer/html_document_view.cc
@@ -214,8 +214,7 @@ void HTMLDocumentView::OnViewDestroyed(View* view) {
 
 void HTMLDocumentView::OnViewInputEvent(View* view, const EventPtr& event) {
   scoped_ptr<blink::WebInputEvent> web_event =
-      TypeConverter<EventPtr, scoped_ptr<blink::WebInputEvent> >::ConvertTo(
-          event);
+      event.To<scoped_ptr<blink::WebInputEvent> >();
   if (web_event)
     web_view_->handleInputEvent(*web_event);
 }