blink: Cleanup class forward declarations

third_party/WebKit/Source/platform/scheduler/child/worker_scheduler_impl.h

 // Copyright 2015 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_SOURCE_PLATFORM_SCHEDULER_CHILD_WORKER_SCHEDULER_IMPL_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_WORKER_SCHEDULER_IMPL_H_
 
 #include "base/macros.h"
 #include "platform/scheduler/child/idle_helper.h"
 #include "platform/scheduler/child/scheduler_helper.h"
 #include "public/platform/scheduler/child/worker_scheduler.h"
 
-namespace base {
-namespace trace_event {
-class ConvertableToTraceFormat;
-}
-}
-
 namespace blink {
 namespace scheduler {
 
 class SchedulerTqmDelegate;
 
 class BLINK_PLATFORM_EXPORT WorkerSchedulerImpl : public WorkerScheduler,
                                                   public IdleHelper::Delegate {
  public:
   explicit WorkerSchedulerImpl(
       scoped_refptr<SchedulerTqmDelegate> main_task_runner);
@@ skipping 29 matching lines @@
   IdleHelper idle_helper_;
   bool initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkerSchedulerImpl);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_WORKER_SCHEDULER_IMPL_H_