[Part 1 of 6] Move MockWebContentsTaskManager into its own file.

chrome/browser/task_management/mock_web_contents_task_manager.cc

-// Copyright 2015 The Chromium Authors. All rights reserved.
+// Copyright 2016 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_management/task_management_browsertest_util.h"
+#include "chrome/browser/task_management/mock_web_contents_task_manager.h"
 
 #include "base/stl_util.h"
 #include "build/build_config.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/resource_reporter/resource_reporter.h"
 #endif  // defined(OS_CHROMEOS)
 
 namespace task_management {
 
-MockWebContentsTaskManager::MockWebContentsTaskManager() {
-}
+MockWebContentsTaskManager::MockWebContentsTaskManager() {}
 
-MockWebContentsTaskManager::~MockWebContentsTaskManager() {
-}
+MockWebContentsTaskManager::~MockWebContentsTaskManager() {}
 
 void MockWebContentsTaskManager::TaskAdded(Task* task) {
   DCHECK(task);
   DCHECK(!ContainsValue(tasks_, task));
   tasks_.push_back(task);
 }
 
 void MockWebContentsTaskManager::TaskRemoved(Task* task) {
   DCHECK(task);
   DCHECK(ContainsValue(tasks_, task));
   tasks_.erase(std::find(tasks_.begin(), tasks_.end(), task));
 }
 
 void MockWebContentsTaskManager::StartObserving() {
 #if defined(OS_CHROMEOS)
   // On ChromeOS, the ResourceReporter needs to be turned off so as not to
   // interfere with the tests.
   chromeos::ResourceReporter::GetInstance()->StopMonitoring();
 #endif  // defined(OS_CHROMEOS)
 
   provider_.SetObserver(this);
 }
 
 void MockWebContentsTaskManager::StopObserving() {
   provider_.ClearObserver();
 }
 
 }  // namespace task_management