Extract touchscreen device management into a generic manager

ash/test/ash_test_helper_unittest.cc

 // Copyright 2013 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/test/ash_test_helper.h"
 
+#include "base/at_exit.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/views/widget/widget.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #endif
 
 // Tests for AshTestHelper. Who will watch the watchers? And who will test
 // the tests?
@@ skipping 11 matching lines @@
   virtual void TearDown() OVERRIDE {
     ash_test_helper_->TearDown();
     testing::Test::TearDown();
   }
 
   ash::test::AshTestHelper* ash_test_helper() {
     return ash_test_helper_.get();
   }
 
  private:
+  base::ShadowingAtExitManager at_exit_;
   base::MessageLoopForUI message_loop_;
   scoped_ptr<ash::test::AshTestHelper> ash_test_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(AshTestHelperTest);
 };
 
 // Ensure that we have initialized enough of Ash to create and show a window.
 TEST_F(AshTestHelperTest, AshTestHelper) {
   // Check initial state.
   EXPECT_TRUE(ash_test_helper()->message_loop());
   EXPECT_TRUE(ash_test_helper()->test_shell_delegate());
   EXPECT_TRUE(ash_test_helper()->CurrentContext());
 
   // Enough state is initialized to create a window.
   using views::Widget;
   scoped_ptr<Widget> w1(new Widget);
   Widget::InitParams params;
   params.ownership = Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.context = ash_test_helper()->CurrentContext();
   w1->Init(params);
   w1->Show();
   EXPECT_TRUE(w1->IsActive());
   EXPECT_TRUE(w1->IsVisible());
 }