Update the window labels if they change in overview mode.

ash/wm/overview/window_selector_item.h

 // Copyright 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 ASH_WM_OVERVIEW_WINDOW_SELECTOR_ITEM_H_
 #define ASH_WM_OVERVIEW_WINDOW_SELECTOR_ITEM_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
+#include "ui/aura/window_observer.h"
 #include "ui/gfx/rect.h"
 #include "ui/views/controls/button/button.h"
 
 namespace aura {
 class Window;
 }
 
 namespace views {
 class Widget;
 }
 
 namespace ash {
 class TransparentActivateWindowButton;
 
 // This class represents an item in overview mode. An item can have one or more
 // windows, of which only one can be activated by keyboard (i.e. alt+tab) but
 // any can be selected with a pointer (touch or mouse).
-class WindowSelectorItem : public views::ButtonListener {
+class WindowSelectorItem : public views::ButtonListener,
+                           public aura::WindowObserver {
  public:
   WindowSelectorItem();
   virtual ~WindowSelectorItem();
 
   // The time for the close buttons and labels to fade in when initially shown
   // on entering overview mode.
   static const int kFadeInMilliseconds;
 
   // Returns the root window on which this item is shown.
   virtual aura::Window* GetRootWindow() = 0;
@@ skipping 38 matching lines @@
   // label is read.
   void SendFocusAlert() const;
 
   const gfx::Rect& bounds() const { return bounds_; }
   const gfx::Rect& target_bounds() const { return target_bounds_; }
 
   // views::ButtonListener:
   virtual void ButtonPressed(views::Button* sender,
                              const ui::Event& event) OVERRIDE;
 
+  // aura::WindowObserver:
+  virtual void OnWindowTitleChanged(aura::Window* window,
+                                    const base::string16& new_title) OVERRIDE;
+
  protected:
   // Sets the bounds of this selector's items to |target_bounds| in
   // |root_window|. If |animate| the windows are animated from their current
   // location.
   virtual void SetItemBounds(aura::Window* root_window,
                              const gfx::Rect& target_bounds,
                              bool animate) = 0;
 
   // Sets the bounds used by the selector item's windows.
   void set_bounds(const gfx::Rect& bounds) { bounds_ = bounds; }
@@ skipping 34 matching lines @@
   // Transparent window on top of the real windows in the overview that
   // activates them on click or tap.
   scoped_ptr<TransparentActivateWindowButton> activate_window_button_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowSelectorItem);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_OVERVIEW_WINDOW_SELECTOR_ITEM_H_