ObserverList::HasObserver now takes a const pointer.

ui/views/widget/widget.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_VIEWS_WIDGET_WIDGET_H_
 #define UI_VIEWS_WIDGET_WIDGET_H_
 
 #include <set>
 #include <stack>
 #include <vector>
@@ skipping 336 matching lines @@
   gfx::NativeView GetNativeView() const;
 
   // Returns the gfx::NativeWindow associated with this Widget. This may return
   // NULL on some platforms if the widget was created with a type other than
   // TYPE_WINDOW or TYPE_PANEL.
   gfx::NativeWindow GetNativeWindow() const;
 
   // Add/remove observer.
   void AddObserver(WidgetObserver* observer);
   void RemoveObserver(WidgetObserver* observer);
-  bool HasObserver(WidgetObserver* observer);
+  bool HasObserver(const WidgetObserver* observer) const;
 
   // Add/remove removals observer.
   void AddRemovalsObserver(WidgetRemovalsObserver* observer);
   void RemoveRemovalsObserver(WidgetRemovalsObserver* observer);
-  bool HasRemovalsObserver(WidgetRemovalsObserver* observer);
+  bool HasRemovalsObserver(const WidgetRemovalsObserver* observer) const;
 
   // Returns the accelerator given a command id. Returns false if there is
   // no accelerator associated with a given id, which is a common condition.
   virtual bool GetAccelerator(int cmd_id, ui::Accelerator* accelerator) const;
 
   // Forwarded from the RootView so that the widget can do any cleanup.
   void ViewHierarchyChanged(const View::ViewHierarchyChangedDetails& details);
 
   // Called right before changing the widget's parent NativeView to do any
   // cleanup.
@@ skipping 572 matching lines @@
   bool movement_disabled_;
 
   ScopedObserver<ui::NativeTheme, ui::NativeThemeObserver> observer_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(Widget);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_WIDGET_H_