Add IsInternal property to gfx::Display

ash/display/event_transformation_handler.cc

Index: ash/display/event_transformation_handler.cc
diff --git a/ash/display/event_transformation_handler.cc b/ash/display/event_transformation_handler.cc
index 380399d8b8ef18e3afa90c54a60cef3c033ab6e9..7ecc6341dbf30756eeda253051fd5861a16493f6 100644
--- a/ash/display/event_transformation_handler.cc
+++ b/ash/display/event_transformation_handler.cc
@@ -4,7 +4,6 @@
 
 #include "ash/display/event_transformation_handler.h"
 
-#include "ash/display/display_manager.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
 #include "ash/wm/coordinate_conversion.h"
@@ -45,8 +44,7 @@ void EventTransformationHandler::OnScrollEvent(ui::ScrollEvent* event) {
   wm::ConvertPointToScreen(target, &point_in_screen);
   const gfx::Display& display =
       Shell::GetScreen()->GetDisplayNearestPoint(point_in_screen);
-  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
-  if (!display_manager->IsInternalDisplayId(display.id()))
+  if (!display.IsInternal())
     scale *= kBoostForNonIntegrated;
 
   event->Scale(scale);