Create OpenClose browser test for TaskManager with necessary refactoring....

chrome/browser/task_manager_browsertest.cc

 // Copyright (c) 2009 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 "chrome/browser/task_manager.h"
 
 #include "chrome/test/in_process_browser_test.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class TaskManagerBrowserTest : public InProcessBrowserTest {
 };
 
 // Regression test for http://crbug.com/11180
+IN_PROC_BROWSER_TEST_F(TaskManagerBrowserTest, OpenClose) {
+  TaskManager::Open();
+  TaskManager::Close();
+}
+
 IN_PROC_BROWSER_TEST_F(TaskManagerBrowserTest, ShutdownWhileOpen) {
   TaskManager::Open();
-}
-
-// TODO(phajdan.jr): Write another test which explicitly closes TaskManager.
-// This requires a small refactoring.
+}