[scheduler] Remove blink::scheduler::TaskQueue from public API.

third_party/WebKit/public/platform/scheduler/base/task_time_observer.h

-// 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.
-
-#ifndef THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_BASE_TASK_TIME_OBSERVER_H_
-#define THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_BASE_TASK_TIME_OBSERVER_H_
-
-#include "base/time/time.h"
-#include "public/platform/WebCommon.h"
-
-namespace blink {
-namespace scheduler {
-
-class TaskQueue;
-
-// TaskTimeObserver provides an API for observing completion of renderer tasks.
-class BLINK_PLATFORM_EXPORT TaskTimeObserver {
- public:
-  TaskTimeObserver() {}
-  virtual ~TaskTimeObserver() {}
-
-  // Callback to be called when task is about to start.
-  // |task_queue| - TaskQueue on which this task will run,
-  // |start_time| - time in seconds when task started to run,
-  virtual void WillProcessTask(TaskQueue* task_queue, double start_time) = 0;
-
-  // Callback to be called when task is completed.
-  // |task_queue| - TaskQueue on which this task was run,
-  // |start_time| - time in seconds when task started to run,
-  // |end_time| - time in seconds when task was completed.
-  virtual void DidProcessTask(TaskQueue* task_queue,
-                              double start_time,
-                              double end_time) = 0;
-
-  // Callback to be called when we enter a nested message loop.
-  virtual void OnBeginNestedMessageLoop() = 0;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(TaskTimeObserver);
-};
-
-}  // namespace scheduler
-}  // namespace blink
-
-#endif  // THIRD_PARTY_WEBKIT_PUBLIC_PLATFORM_SCHEDULER_BASE_TASK_TIME_OBSERVER_H_