linux_aura: Double clicking the titlebar should toggle maximized.

ui/views/widget/desktop_aura/x11_window_event_filter.h

Index: ui/views/widget/desktop_aura/x11_window_event_filter.h
diff --git a/ui/views/widget/desktop_aura/x11_window_event_filter.h b/ui/views/widget/desktop_aura/x11_window_event_filter.h
index ee4d37be0ddeff145053f150092a367e5694b5eb..d172958cc8f64c6a0931b7b4a664747f4a1cc9c8 100644
--- a/ui/views/widget/desktop_aura/x11_window_event_filter.h
+++ b/ui/views/widget/desktop_aura/x11_window_event_filter.h
@@ -26,12 +26,14 @@ class Point;
 }
 
 namespace views {
+class DesktopRootWindowHost;
 class NativeWidgetAura;
 
 // An EventFilter that sets properties on X11 windows.
 class VIEWS_EXPORT X11WindowEventFilter : public ui::EventHandler {
  public:
-  explicit X11WindowEventFilter(aura::RootWindow* root_window);
+  X11WindowEventFilter(aura::RootWindow* root_window,
+                       DesktopRootWindowHost* root_window_host);
   virtual ~X11WindowEventFilter();
 
   // Changes whether borders are shown on this |root_window|.
@@ -55,6 +57,8 @@ class VIEWS_EXPORT X11WindowEventFilter : public ui::EventHandler {
 
   ui::X11AtomCache atom_cache_;
 
+  DesktopRootWindowHost* root_window_host_;
+
   // True if |xwindow_| is the current _NET_ACTIVE_WINDOW.
   bool is_active_;