aura: Remove NotifyAncestorWindowTransformed in window observer.

ui/aura/window.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 UI_AURA_WINDOW_H_
 #define UI_AURA_WINDOW_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 400 matching lines @@
   // during the call (by an observer), otherwise true.
   bool NotifyWindowVisibilityChangedAtReceiver(aura::Window* target,
                                                bool visible);
   // Notifies this window and its child hierarchy. Returns false if
   // |this| was deleted during the call (by an observer), otherwise
   // true.
   bool NotifyWindowVisibilityChangedDown(aura::Window* target, bool visible);
   // Notifies this window and its parent hierarchy.
   void NotifyWindowVisibilityChangedUp(aura::Window* target, bool visible);
 
-  // Notifies this window and its child hierarchy of a transform applied to
-  // |source|.
-  void NotifyAncestorWindowTransformed(Window* source);
-
   // Overridden from ui::LayerDelegate:
   void OnPaintLayer(const ui::PaintContext& context) override;
   void OnDelegatedFrameDamage(const gfx::Rect& damage_rect_in_dip) override;
   void OnLayerBoundsChanged(const gfx::Rect& old_bounds) override;
 
   // Overridden from ui::EventTarget:
   bool CanAcceptEvent(const ui::Event& event) override;
   EventTarget* GetParentTarget() override;
   std::unique_ptr<ui::EventTargetIterator> GetChildIterator() const override;
   ui::EventTargeter* GetEventTargeter() override;
@@ skipping 52 matching lines @@
   bool ignore_events_;
 
   base::ObserverList<WindowObserver, true> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(Window);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_H_