[ash-md] Animates overview shield in and out

ash/common/wm/overview/window_selector.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/common/wm/overview/window_selector.h"
 
 #include <algorithm>
 #include <functional>
 #include <set>
 #include <utility>
@@ skipping 378 matching lines @@
     PanelLayoutManager::Get(window)->SetShowCalloutWidgets(true);
   }
 
   size_t remaining_items = 0;
   for (std::unique_ptr<WindowGrid>& window_grid : grid_list_) {
     for (WindowSelectorItem* window_selector_item : window_grid->window_list())
       window_selector_item->RestoreWindow();
     remaining_items += window_grid->size();
   }
 
+  for (std::unique_ptr<WindowGrid>& window_grid : grid_list_)
+    window_grid->Shutdown();
+
   DCHECK(num_items_ >= remaining_items);
   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.OverviewClosedItems",
                            num_items_ - remaining_items);
   UMA_HISTOGRAM_MEDIUM_TIMES("Ash.WindowSelector.TimeInOverview",
                              base::Time::Now() - overview_start_time_);
 
   // Record metrics related to text filtering.
   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.TextFilteringStringLength",
                            text_filter_string_length_);
   UMA_HISTOGRAM_COUNTS_100("Ash.WindowSelector.TextFilteringTextfieldCleared",
@@ skipping 294 matching lines @@
   for (size_t i = 0; i <= grid_list_.size() &&
                      grid_list_[selected_grid_index_]->Move(direction, animate);
        i++) {
     selected_grid_index_ =
         (selected_grid_index_ + display_direction + grid_list_.size()) %
         grid_list_.size();
   }
 }
 
 }  // namespace ash