Assert RendererScheduler thread usage

content/renderer/scheduler/web_scheduler_impl.h

Index: content/renderer/scheduler/web_scheduler_impl.h
diff --git a/content/renderer/scheduler/web_scheduler_impl.h b/content/renderer/scheduler/web_scheduler_impl.h
index 4f4100251f9241183ccee12009dc70dc9d659d76..4512d85e832bd65bbf1d06fc7b9e346d9537a579 100644
--- a/content/renderer/scheduler/web_scheduler_impl.h
+++ b/content/renderer/scheduler/web_scheduler_impl.h
@@ -12,6 +12,10 @@
 #include "third_party/WebKit/public/platform/WebScheduler.h"
 #include "third_party/WebKit/public/platform/WebThread.h"
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace content {
 
 class RendererScheduler;
@@ -36,6 +40,7 @@ class CONTENT_EXPORT WebSchedulerImpl : public blink::WebScheduler {
 
   RendererScheduler* renderer_scheduler_;
   scoped_refptr<SingleThreadIdleTaskRunner> idle_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> loading_task_runner_;
 };
 
 }  // namespace content