[Reland] Post loading tasks on the appropriate WebFrameScheduler's queue

components/scheduler/child/web_task_runner_impl.cc

Index: components/scheduler/child/web_task_runner_impl.cc
diff --git a/components/scheduler/child/web_task_runner_impl.cc b/components/scheduler/child/web_task_runner_impl.cc
index b4794a4c545b7ddcb734c69160c966a0a2675041..56591ac412c237ea5b9ea633540cd5c7e0ee1b21 100644
--- a/components/scheduler/child/web_task_runner_impl.cc
+++ b/components/scheduler/child/web_task_runner_impl.cc
@@ -36,4 +36,8 @@ void WebTaskRunnerImpl::postDelayedTask(
       base::TimeDelta::FromMillisecondsD(delayMs));
 }
 
+blink::WebTaskRunner* WebTaskRunnerImpl::clone() {
+  return new WebTaskRunnerImpl(task_runner_);
+}
+
 }  // namespace scheduler