Move and rename TaskTimeTracker to public interface exposed to WebThread, use in WebPerf Agent.

third_party/WebKit/public/platform/scheduler/child/webthread_base.h

 // 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.
 
 #ifndef THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_CHILD_WEBTHREAD_BASE_H_
 #define THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_CHILD_WEBTHREAD_BASE_H_
 
 #include <map>
 #include <memory>
 
@@ skipping 15 matching lines @@
   PlatformThreadId threadId() const override = 0;
 
   virtual void postIdleTask(const WebTraceLocation& location,
                             IdleTask* idle_task);
   virtual void postIdleTaskAfterWakeup(const WebTraceLocation& location,
                                        IdleTask* idle_task);
 
   void addTaskObserver(TaskObserver* observer) override;
   void removeTaskObserver(TaskObserver* observer) override;
 
+  void addTaskTimeObserver(TaskTimeObserver* task_time_observer) override;
+  void removeTaskTimeObserver(TaskTimeObserver* task_time_observer) override;
+
   // Returns the base::Bind-compatible task runner for posting tasks to this
   // thread. Can be called from any thread.
   virtual base::SingleThreadTaskRunner* GetTaskRunner() const = 0;
 
   // Returns the base::Bind-compatible task runner for posting idle tasks to
   // this thread. Can be called from any thread.
   virtual scheduler::SingleThreadIdleTaskRunner* GetIdleTaskRunner() const = 0;
 
  protected:
   class TaskObserverAdapter;
 
   WebThreadBase();
 
   virtual void AddTaskObserverInternal(
       base::MessageLoop::TaskObserver* observer);
   virtual void RemoveTaskObserverInternal(
       base::MessageLoop::TaskObserver* observer);
 
+  virtual void AddTaskTimeObserverInternal(TaskTimeObserver*) {}
+  virtual void RemoveTaskTimeObserverInternal(TaskTimeObserver*) {}
+
   static void RunWebThreadIdleTask(
       std::unique_ptr<WebThread::IdleTask> idle_task,
       base::TimeTicks deadline);
 
  private:
   typedef std::map<TaskObserver*, TaskObserverAdapter*> TaskObserverMap;
   TaskObserverMap task_observer_map_;
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_CHILD_WEBTHREAD_BASE_H_