ObserverList::HasObserver now takes a const pointer.

ui/aura/window.cc

 // 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.
 
 #include "ui/aura/window.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 645 matching lines @@
 void Window::AddObserver(WindowObserver* observer) {
   observer->OnObservingWindow(this);
   observers_.AddObserver(observer);
 }
 
 void Window::RemoveObserver(WindowObserver* observer) {
   observer->OnUnobservingWindow(this);
   observers_.RemoveObserver(observer);
 }
 
-bool Window::HasObserver(WindowObserver* observer) {
+bool Window::HasObserver(const WindowObserver* observer) const {
   return observers_.HasObserver(observer);
 }
 
 bool Window::ContainsPointInRoot(const gfx::Point& point_in_root) const {
   const Window* root_window = GetRootWindow();
   if (!root_window)
     return false;
   gfx::Point local_point(point_in_root);
   ConvertPointToTarget(root_window, this, &local_point);
   return gfx::Rect(GetTargetBounds().size()).Contains(local_point);
@@ skipping 774 matching lines @@
       return window;
     if (offset)
       *offset += window->bounds().OffsetFromOrigin();
   }
   if (offset)
     *offset = gfx::Vector2d();
   return NULL;
 }
 
 }  // namespace aura