Assert RendererScheduler thread usage

content/renderer/scheduler/web_scheduler_impl.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 CONTENT_RENDERER_SCHEDULER_WEB_SCHEDULER_IMPL_H_
 #define CONTENT_RENDERER_SCHEDULER_WEB_SCHEDULER_IMPL_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebScheduler.h"
 #include "third_party/WebKit/public/platform/WebThread.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace content {
 
 class RendererScheduler;
 class SingleThreadIdleTaskRunner;
 
 class CONTENT_EXPORT WebSchedulerImpl : public blink::WebScheduler {
  public:
   WebSchedulerImpl(RendererScheduler* renderer_scheduler);
   ~WebSchedulerImpl() override;
 
   virtual bool shouldYieldForHighPriorityWork();
   virtual void postIdleTask(const blink::WebTraceLocation& location,
                             blink::WebScheduler::IdleTask* task);
   virtual void postLoadingTask(const blink::WebTraceLocation& location,
                                blink::WebThread::Task* task);
   virtual void shutdown();
 
  private:
   static void runIdleTask(scoped_ptr<blink::WebScheduler::IdleTask> task,
                           base::TimeTicks deadline);
   static void runTask(scoped_ptr<blink::WebThread::Task> task);
 
   RendererScheduler* renderer_scheduler_;
   scoped_refptr<SingleThreadIdleTaskRunner> idle_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> loading_task_runner_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_SCHEDULER_WEB_SCHEDULER_IMPL_H_