linux aura: Support touch events.

ui/views/widget/desktop_aura/desktop_root_window_host_x11.h

Index: ui/views/widget/desktop_aura/desktop_root_window_host_x11.h
diff --git a/ui/views/widget/desktop_aura/desktop_root_window_host_x11.h b/ui/views/widget/desktop_aura/desktop_root_window_host_x11.h
index 8309cfc7e6ef26366c29474a921793e3dd83a397..1a0cb847e3800c5938e3c8df17ff0c0ae9bcae62 100644
--- a/ui/views/widget/desktop_aura/desktop_root_window_host_x11.h
+++ b/ui/views/widget/desktop_aura/desktop_root_window_host_x11.h
@@ -180,6 +180,11 @@ private:
   // and dispatch it to that host instead.
   void DispatchMouseEvent(ui::MouseEvent* event);
 
+  // Dispatches a touch event, taking capture into account. If a different host
+  // has capture, then touch-press events are translated to its coordinate space
+  // and dispatched to that host instead.
+  void DispatchTouchEvent(ui::TouchEvent* event);
+
   // Resets the window region for the current widget bounds if necessary.
   void ResetWindowRegion();