Update the window labels if they change in overview mode.

ash/wm/overview/window_selector_panels.cc

 // 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.
 
 #include "ash/wm/overview/window_selector_panels.h"
 
 #include "ash/screen_util.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/overview/scoped_transform_overview_window.h"
@@ skipping 74 matching lines @@
     : panels_root_window_(panels_root_window) {
   static_cast<PanelLayoutManager*>(
       Shell::GetContainer(panels_root_window_, kShellWindowId_PanelContainer)->
           layout_manager())->SetShowCalloutWidgets(false);
 }
 
 WindowSelectorPanels::~WindowSelectorPanels() {
   static_cast<PanelLayoutManager*>(
       Shell::GetContainer(panels_root_window_, kShellWindowId_PanelContainer)->
           layout_manager())->SetShowCalloutWidgets(true);
+  for (WindowList::iterator iter = transform_windows_.begin();
+      iter != transform_windows_.end(); iter++) {
+    (*iter)->window()->RemoveObserver(this);
+  }
 }
 
 void WindowSelectorPanels::AddWindow(aura::Window* window) {
   DCHECK(window->GetRootWindow() == panels_root_window_);
+  window->AddObserver(this);
   transform_windows_.push_back(new ScopedTransformPanelWindow(window));
 }
 
 aura::Window* WindowSelectorPanels::GetRootWindow() {
   return transform_windows_.front()->window()->GetRootWindow();
 }
 
 bool WindowSelectorPanels::HasSelectableWindow(const aura::Window* window) {
   for (WindowList::const_iterator iter = transform_windows_.begin();
        iter != transform_windows_.end(); ++iter) {
@@ skipping 23 matching lines @@
 }
 
 aura::Window* WindowSelectorPanels::SelectionWindow() {
   return transform_windows_.front()->window();
 }
 
 void WindowSelectorPanels::RemoveWindow(const aura::Window* window) {
   for (WindowList::iterator iter = transform_windows_.begin();
        iter != transform_windows_.end(); ++iter) {
     if ((*iter)->window() == window) {
+      (*iter)->window()->RemoveObserver(this);
       (*iter)->OnWindowDestroyed();
       transform_windows_.erase(iter);
       break;
     }
   }
   WindowSelectorItem::RemoveWindow(window);
 }
 
 bool WindowSelectorPanels::empty() const {
   return transform_windows_.empty();
 }
 
 void WindowSelectorPanels::PrepareForOverview() {
   // |panel_windows| will hold all the windows in the panel container, sorted
   // according to their stacking order.
   const aura::Window::Windows panels =
-      transform_windows_[0]->window()->parent()->children();
+      transform_windows_.front()->window()->parent()->children();
 
   // Call PrepareForOverview() in the reverse stacking order so that the
   // transparent windows that handle the events are in the correct stacking
   // order.
   size_t transformed_windows = 0;
   for (aura::Window::Windows::const_reverse_iterator iter = panels.rbegin();
       iter != panels.rend(); iter++) {
     for (size_t j = 0; j < transform_windows_.size(); ++j) {
       if (transform_windows_[j]->window() == (*iter)) {
         transform_windows_[j]->PrepareForOverview();
@@ skipping 24 matching lines @@
     transform.Translate(bounding_rect.x() - bounds.x(),
                         bounding_rect.y() - bounds.y());
     transform.PreconcatTransform(bounding_transform);
     transform.Translate(bounds.x() - bounding_rect.x(),
                         bounds.y() - bounding_rect.y());
     (*iter)->SetTransform(root_window, transform, animate);
   }
 }
 
 }  // namespace ash