Keep the SystemModalContainerEventHandler added

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 7b109fe85c8f754975714256635c52853da275ea..c5484184e1acc91906f9a773934f46aa627e76a3 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -527,6 +527,9 @@ class ASH_EXPORT Shell : public SystemModalContainerEventFilterDelegate,
 
   GPUSupport* gpu_support() { return gpu_support_.get(); }
 
+  // SystemModalContainerEventFilterDelegate:
+  bool CanWindowReceiveEvents(aura::Window* window) override;
+
  private:
   FRIEND_TEST_ALL_PREFIXES(ExtendedDesktopTest, TestCursor);
   FRIEND_TEST_ALL_PREFIXES(WindowManagerTest, MouseEventCursors);
@@ -553,9 +556,6 @@ class ASH_EXPORT Shell : public SystemModalContainerEventFilterDelegate,
   // Prepares the shelf to be deleted.
   void ShutdownShelf();
 
-  // ash::SystemModalContainerEventFilterDelegate overrides:
-  bool CanWindowReceiveEvents(aura::Window* window) override;
-
   // Overridden from ui::EventTarget:
   bool CanAcceptEvent(const ui::Event& event) override;
   EventTarget* GetParentTarget() override;