events: Update mouse-event handlers to not return EventResult.

ash/wm/activation_controller.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 "ash/wm/activation_controller.h"
 
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/activation_controller_delegate.h"
@@ skipping 257 matching lines @@
   if (gained_focus)
     ActivateWindow(GetActivatableWindow(gained_focus, NULL));
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // ActivationController, ui::EventHandler implementation:
 
 void ActivationController::OnKeyEvent(ui::KeyEvent* event) {
 }
 
-ui::EventResult ActivationController::OnMouseEvent(ui::MouseEvent* event) {
+void ActivationController::OnMouseEvent(ui::MouseEvent* event) {
   if (event->type() == ui::ET_MOUSE_PRESSED)
     FocusWindowWithEvent(event);
-  return ui::ER_UNHANDLED;
 }
 
 void ActivationController::OnScrollEvent(ui::ScrollEvent* event) {
 }
 
 void ActivationController::OnTouchEvent(ui::TouchEvent* event) {
   if (event->type() == ui::ET_TOUCH_PRESSED)
     FocusWindowWithEvent(event);
 }
 
@@ skipping 131 matching lines @@
   aura::Window* window = static_cast<aura::Window*>(event->target());
   window = delegate_->WillFocusWindow(window);
   if (GetActiveWindow() != window) {
     aura::client::GetFocusClient(window)->FocusWindow(
         FindFocusableWindowFor(window), event);
   }
 }
 
 }  // namespace internal
 }  // namespace ash