Don't treat minimized windows as lower priority in MRU list (for Alt+Tab

ash/common/wm/overview/window_grid.h

 // Copyright 2014 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_COMMON_WM_OVERVIEW_WINDOW_GRID_H_
 #define ASH_COMMON_WM_OVERVIEW_WINDOW_GRID_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <set>
 #include <vector>
 
 #include "ash/common/wm/overview/window_selector.h"
 #include "ash/common/wm_window_observer.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
+#include "base/scoped_observer.h"
 
 namespace views {
 class Widget;
 }
 
 namespace wm {
 class Shadow;
 }
 
 namespace ash {
@@ skipping 137 matching lines @@
 
   // Root window the grid is in.
   WmWindow* root_window_;
 
   // Pointer to the window selector that spawned this grid.
   WindowSelector* window_selector_;
 
   // Vector containing all the windows in this grid.
   ScopedVector<WindowSelectorItem> window_list_;
 
-  // Vector containing the observed windows.
-  std::set<WmWindow*> observed_windows_;
+  ScopedObserver<WmWindow, WindowGrid> window_observer_;
 
   // Widget that darkens the screen background.
   std::unique_ptr<views::Widget> shield_widget_;
 
   // Widget that indicates to the user which is the selected window.
   std::unique_ptr<views::Widget> selection_widget_;
 
   // Shadow around the selector.
   std::unique_ptr<::wm::Shadow> selector_shadow_;
 
   // Current selected window position.
   size_t selected_index_;
 
   // Number of columns in the grid.
   size_t num_columns_;
 
+  // True only after all windows have been prepared for overview.
+  bool prepared_for_overview_;
+
   DISALLOW_COPY_AND_ASSIGN(WindowGrid);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_OVERVIEW_WINDOW_GRID_H_