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

ui/views/widget/desktop_aura/desktop_activation_client.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/widget/desktop_aura/desktop_activation_client.h"
 
 #include "base/auto_reset.h"
 #include "base/compiler_specific.h"
 #include "ui/aura/client/activation_delegate.h"
 #include "ui/aura/client/activation_change_observer.h"
@@ skipping 143 matching lines @@
 bool DesktopActivationClient::CanActivateWindow(aura::Window* window) const {
   return window &&
       window->IsVisible() &&
       (!aura::client::GetActivationDelegate(window) ||
        aura::client::GetActivationDelegate(window)->ShouldActivate());
 }
 
 void DesktopActivationClient::OnKeyEvent(ui::KeyEvent* event) {
 }
 
-ui::EventResult DesktopActivationClient::OnMouseEvent(ui::MouseEvent* event) {
+void DesktopActivationClient::OnMouseEvent(ui::MouseEvent* event) {
   if (event->type() == ui::ET_MOUSE_PRESSED)
     FocusWindowWithEvent(event);
-  return ui::ER_UNHANDLED;
 }
 
 void DesktopActivationClient::OnScrollEvent(ui::ScrollEvent* event) {
 }
 
 void DesktopActivationClient::OnTouchEvent(ui::TouchEvent* event) {
 }
 
 void DesktopActivationClient::OnGestureEvent(ui::GestureEvent* event) {
   if (event->type() == ui::ET_GESTURE_BEGIN &&
       event->details().touch_points() == 1) {
     FocusWindowWithEvent(event);
   }
 }
 
 void DesktopActivationClient::FocusWindowWithEvent(const ui::Event* event) {
   aura::Window* window = static_cast<aura::Window*>(event->target());
   if (GetActiveWindow() != window) {
     aura::client::GetFocusClient(window)->FocusWindow(
         FindFocusableWindowFor(window), event);
   }
 }
 
 }  // namespace views