Sets X11WholeScreenMoveLoop as OverrideDispatcher to get events even before grab is granted

ui/views/widget/desktop_aura/x11_whole_screen_move_loop.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_X11_WHOLE_SCREEN_MOVE_LOOP_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_X11_WHOLE_SCREEN_MOVE_LOOP_H_
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
 #include "ui/events/platform/platform_event_dispatcher.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/vector2d_f.h"
 #include "ui/views/widget/desktop_aura/x11_whole_screen_move_loop_delegate.h"
 
 typedef struct _XDisplay XDisplay;
 
 namespace aura {
 class Window;
 }
 
+namespace ui {
+class ScopedEventDispatcher;
+}
+
 namespace views {
 
 class Widget;
 
 // Runs a nested message loop and grabs the mouse. This is used to implement
 // dragging.
 class X11WholeScreenMoveLoop : public ui::PlatformEventDispatcher {
  public:
   explicit X11WholeScreenMoveLoop(X11WholeScreenMoveLoopDelegate* delegate);
   virtual ~X11WholeScreenMoveLoop();
@@ skipping 32 matching lines @@
   // (defined as having a pixel with alpha > 32). If so, return true.
   bool CheckIfIconValid();
 
   // Dispatch mouse movement event to |delegate_| in a posted task.
   void DispatchMouseMovement();
 
   X11WholeScreenMoveLoopDelegate* delegate_;
 
   // Are we running a nested message loop from RunMoveLoop()?
   bool in_move_loop_;
+  scoped_ptr<ui::ScopedEventDispatcher> nested_dispatcher_;
 
   bool should_reset_mouse_flags_;
 
   // An invisible InputOnly window . We create this window so we can track the
   // cursor wherever it goes on screen during a drag, since normal windows
   // don't receive pointer motion events outside of their bounds.
   ::Window grab_input_window_;
 
   base::Closure quit_closure_;
 
   // Keeps track of whether the move-loop is cancled by the user (e.g. by
   // pressing escape).
   bool canceled_;
 
   // A Widget is created during the drag if there is an image available to be
   // used during the drag.
   scoped_ptr<Widget> drag_widget_;
   gfx::ImageSkia drag_image_;
   gfx::Vector2dF drag_offset_;
   XMotionEvent last_xmotion_;
   base::WeakPtrFactory<X11WholeScreenMoveLoop> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(X11WholeScreenMoveLoop);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_X11_WHOLE_SCREEN_MOVE_LOOP_H_