linux/x11: Fix event dispatch in menus in High DPI.

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
index d6b5cc842dce6ce5f25bb40a0d886928508f2ba6..44db8613c85a82b742bd6b62f7fc63ac51340b2d 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
@@ -164,6 +164,7 @@ class VIEWS_EXPORT DesktopWindowTreeHostX11
   ui::EventProcessor* GetEventProcessor() override;
 
  private:
+  friend class DesktopWindowTreeHostX11HighDPITest;
   // Initializes our X11 surface to draw on. This method performs all
   // initialization related to talking to the X11 server.
   void InitX11Window(const Widget::InitParams& params);
@@ -209,6 +210,11 @@ class VIEWS_EXPORT DesktopWindowTreeHostX11
   // and dispatched to that host instead.
   void DispatchTouchEvent(ui::TouchEvent* event);
 
+  // Updates the location of |located_event| to be in |host|'s coordinate system
+  // so that it can be dispatched to |host|.
+  void UpdateEventLocationForDifferentHost(ui::LocatedEvent* located_event,
+                                           DesktopWindowTreeHostX11* host);
+
   // Resets the window region for the current widget bounds if necessary.
   void ResetWindowRegion();