Keep non-key event handling in-house for NativeWidgetMus

ui/views/mus/native_widget_mus.h

Index: ui/views/mus/native_widget_mus.h
diff --git a/ui/views/mus/native_widget_mus.h b/ui/views/mus/native_widget_mus.h
index 348a876e659737321bf2b60224e520f58af3ceab..1ebb5601129f93c33072f5a62e4589182a577d0f 100644
--- a/ui/views/mus/native_widget_mus.h
+++ b/ui/views/mus/native_widget_mus.h
@@ -29,6 +29,7 @@ class DefaultCaptureClient;
 class ScreenPositionClient;
 class WindowTreeClient;
 }
+class EnvInputStateController;
 class Window;
 }
 
@@ -268,6 +269,7 @@ private:
   std::unique_ptr<aura::client::WindowTreeClient> window_tree_client_;
   std::unique_ptr<aura::client::ScreenPositionClient> screen_position_client_;
   std::unique_ptr<wm::CursorManager> cursor_manager_;
+  std::unique_ptr<aura::EnvInputStateController> aura_env_controller_;
   base::WeakPtrFactory<NativeWidgetMus> close_widget_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeWidgetMus);