Fixes _NET_ACTIVE_WINDOW support check in order to not always return no.

ui/views/widget/desktop_aura/x11_desktop_handler.h

Index: ui/views/widget/desktop_aura/x11_desktop_handler.h
diff --git a/ui/views/widget/desktop_aura/x11_desktop_handler.h b/ui/views/widget/desktop_aura/x11_desktop_handler.h
index 085a9e460957ad1a57b6087246a1af448ce1b98c..72651a394ec959cd08d62a2dd1e175540ea733b8 100644
--- a/ui/views/widget/desktop_aura/x11_desktop_handler.h
+++ b/ui/views/widget/desktop_aura/x11_desktop_handler.h
@@ -51,6 +51,12 @@ class VIEWS_EXPORT X11DesktopHandler : public base::MessagePumpDispatcher,
   virtual void OnWindowInitialized(aura::Window* window) OVERRIDE;
   virtual void OnWillDestroyEnv() OVERRIDE;
 
+  // Allows to override wm_supports_active_window_ value for tests. If the WM
+  // supports _NET_ACTIVE_WINDOW, activation is async otherwise it is sync.
+  void SetWMSupportsActiveWindowForTests(bool value) {
+    wm_supports_active_window_ = value;
+  }
+
  private:
   explicit X11DesktopHandler();
   virtual ~X11DesktopHandler();