events: Start changing EventHandler interface to not return a value.

ui/views/corewm/activation_change_shim.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_COREWM_ACTIVATION_CHANGE_SHIM_
 #define UI_VIEWS_COREWM_ACTIVATION_CHANGE_SHIM_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "ui/aura/client/activation_change_observer.h"
@@ skipping 16 matching lines @@
       public ui::EventHandler {
  protected:
   explicit ActivationChangeShim(ui::EventTarget* target);
   virtual ~ActivationChangeShim();
 
   // Overridden from aura::client::ActivationChangeObserver:
   virtual void OnWindowActivated(aura::Window* active,
                                  aura::Window* old_active) OVERRIDE;
 
   // Overridden from ui::EventHandler:
-  virtual ui::EventResult OnEvent(ui::Event* event) OVERRIDE;
+  virtual void OnEvent(ui::Event* event) OVERRIDE;
 
  private:
   ui::EventTarget* target_;
 
   DISALLOW_COPY_AND_ASSIGN(ActivationChangeShim);
 };
 
 }  // namespace corewm
 }  // namespace views
 
 #endif  // UI_VIEWS_COREWM_ACTIVATION_CHANGE_SHIM_