MacViews: Fix ViewTest.HandleAccelerator by faking window activation

ui/views/test/views_test_helper.cc

 // Copyright 2014 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/test/views_test_helper.h"
 
 namespace views {
 
-ViewsTestHelper::ViewsTestHelper() {
-}
+ViewsTestHelper::ViewsTestHelper() {}
 
-ViewsTestHelper::~ViewsTestHelper() {
-}
+ViewsTestHelper::~ViewsTestHelper() {}
 
-void ViewsTestHelper::SetUp() {
-}
+void ViewsTestHelper::SetUp() {}
 
-void ViewsTestHelper::TearDown() {
-}
+void ViewsTestHelper::TearDown() {}
 
 gfx::NativeWindow ViewsTestHelper::GetContext() {
   return NULL;
 }
 
+void ViewsTestHelper::EnableFakeWindowActivation() {}
+
 }  // namespace views