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

ui/views/corewm/activation_change_shim.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/views/corewm/activation_change_shim.h"
 
 #include "base/command_line.h"
 #include "ui/aura/window.h"
 #include "ui/base/events/event_target.h"
 #include "ui/views/corewm/corewm_switches.h"
@@ skipping 16 matching lines @@
 
 ActivationChangeShim::~ActivationChangeShim() {
   if (UseFocusController() && target_)
     target_->RemovePreTargetHandler(this);
 }
 
 void ActivationChangeShim::OnWindowActivated(aura::Window* active,
                                              aura::Window* old_active) {
 }
 
-ui::EventResult ActivationChangeShim::OnEvent(ui::Event* event) {
+void ActivationChangeShim::OnEvent(ui::Event* event) {
   if (event->type() == FocusChangeEvent::activation_changed_event_type()) {
     DCHECK(UseFocusController());
     FocusChangeEvent* fce = static_cast<FocusChangeEvent*>(event);
     OnWindowActivated(static_cast<aura::Window*>(event->target()),
                       static_cast<aura::Window*>(fce->last_focus()));
   }
-  return EventHandler::OnEvent(event);
+  EventHandler::OnEvent(event);
 }
 
 }  // namespace corewm
 }  // namespace views