Converts MruWindowTracker to work with common types

ash/aura/wm_window_aura.h

 // Copyright 2016 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_AURA_WM_WINDOW_AURA_H_
 #define ASH_AURA_WM_WINDOW_AURA_H_
 
 #include "ash/ash_export.h"
 #include "ash/common/wm_window.h"
 #include "base/macros.h"
@@ skipping 12 matching lines @@
 
   // Returns a WmWindow for an aura::Window, creating if necessary. |window| may
   // be null, in which case null is returned.
   static WmWindow* Get(aura::Window* window) {
     return const_cast<WmWindow*>(Get(const_cast<const aura::Window*>(window)));
   }
   static const WmWindow* Get(const aura::Window* window);
 
   static std::vector<WmWindow*> FromAuraWindows(
       const std::vector<aura::Window*>& aura_windows);
+  static std::vector<aura::Window*> ToAuraWindows(
+      const std::vector<WmWindow*>& windows);
 
   static aura::Window* GetAuraWindow(WmWindow* wm_window) {
     return const_cast<aura::Window*>(
         GetAuraWindow(const_cast<const WmWindow*>(wm_window)));
   }
   static const aura::Window* GetAuraWindow(const WmWindow* wm_window);
 
   aura::Window* aura_window() { return window_; }
   const aura::Window* aura_window() const { return window_; }
 
@@ skipping 99 matching lines @@
       BoundsInScreenBehavior behavior) override;
   void SetSnapsChildrenToPhysicalPixelBoundary() override;
   void SnapToPixelBoundaryIfNecessary() override;
   void SetChildrenUseExtendedHitRegion() override;
   void SetDescendantsStayInSameRootWindow(bool value) override;
   void AddObserver(WmWindowObserver* observer) override;
   void RemoveObserver(WmWindowObserver* observer) override;
 
  private:
   // aura::WindowObserver:
+  void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override;
   void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
   void OnWindowStackingChanged(aura::Window* window) override;
   void OnWindowPropertyChanged(aura::Window* window,
                                const void* key,
                                intptr_t old) override;
   void OnWindowBoundsChanged(aura::Window* window,
                              const gfx::Rect& old_bounds,
                              const gfx::Rect& new_bounds) override;
   void OnWindowDestroying(aura::Window* window) override;
+  void OnWindowDestroyed(aura::Window* window) override;
   void OnWindowVisibilityChanging(aura::Window* window, bool visible) override;
   void OnWindowTitleChanged(aura::Window* window) override;
 
   aura::Window* window_;
 
   base::ObserverList<WmWindowObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(WmWindowAura);
 };
 
 }  // namespace ash
 
 #endif  // ASH_AURA_WM_WINDOW_AURA_H_