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

mojo/services/native_viewport/native_viewport_impl.cc

Index: mojo/services/native_viewport/native_viewport_impl.cc
diff --git a/mojo/services/native_viewport/native_viewport_impl.cc b/mojo/services/native_viewport/native_viewport_impl.cc
index 9d6ff23f0778c116a49686e186500d90d0bf4575..47de6929265eb8cbcd404f35cb0eae74b3ed964f 100644
--- a/mojo/services/native_viewport/native_viewport_impl.cc
+++ b/mojo/services/native_viewport/native_viewport_impl.cc
@@ -118,9 +118,8 @@ bool NativeViewportImpl::OnEvent(ui::Event* ui_event) {
     return false;
 
   client()->OnEvent(
-      TypeConverter<EventPtr, ui::Event>::ConvertFrom(*ui_event),
-      base::Bind(&NativeViewportImpl::AckEvent,
-                 weak_factory_.GetWeakPtr()));
+      Event::From(*ui_event),
+      base::Bind(&NativeViewportImpl::AckEvent, weak_factory_.GetWeakPtr()));
   waiting_for_event_ack_ = true;
   return false;
 }