Change overview mode to so that docked panel windows are not grouped together.

ash/wm/panels/panel_layout_manager.h

 // Copyright (c) 2012 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_PANELS_PANEL_LAYOUT_MANAGER_H_
 #define ASH_WM_PANELS_PANEL_LAYOUT_MANAGER_H_
 
 #include <list>
 
 #include "ash/ash_export.h"
@@ skipping 77 matching lines @@
   void OnWindowRemovedFromLayout(aura::Window* child) override;
   void OnChildWindowVisibilityChanged(aura::Window* child,
                                       bool visibile) override;
   void SetChildBounds(aura::Window* child,
                       const gfx::Rect& requested_bounds) override;
 
   // Overridden from ShelfIconObserver
   void OnShelfIconPositionsChanged() override;
 
   // Overridden from ShellObserver
+  void OnOverviewModeStarting() override;
+  void OnOverviewModeEnding() override;
   void OnShelfAlignmentChanged(aura::Window* root_window) override;
 
   // Overridden from aura::WindowObserver
   void OnWindowPropertyChanged(aura::Window* window,
                                const void* key,
                                intptr_t old) override;
 
   // Overridden from ash::wm::WindowStateObserver
   void OnPostWindowStateTypeChange(wm::WindowState* window_state,
                                    wm::WindowStateType old_type) override;
@@ skipping 76 matching lines @@
   // When not NULL, the shelf is hidden (i.e. full screen) and this tracks the
   // set of panel windows which have been temporarily hidden and need to be
   // restored when the shelf becomes visible again.
   scoped_ptr<aura::WindowTracker> restore_windows_on_shelf_visible_;
 
   // The last active panel. Used to maintain stacking order even if no panels
   // are currently focused.
   aura::Window* last_active_panel_;
   base::WeakPtrFactory<PanelLayoutManager> weak_factory_;
 
+  // Track whether overview mode is active. Used to suppress layouts when it is.
+  bool overview_mode_active_;
+
   DISALLOW_COPY_AND_ASSIGN(PanelLayoutManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_PANELS_PANEL_LAYOUT_MANAGER_H_