[Prerender] Restore request priorities when swapped in

content/browser/loader/resource_dispatcher_host_impl.cc

Index: content/browser/loader/resource_dispatcher_host_impl.cc
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index 90ed1ce30ae58f909973c8347dac8a4a9f14c956..ccd64e48ed641789e1298f52134e8620c8925298 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -498,6 +498,12 @@ void ResourceDispatcherHostImpl::RegisterInterceptor(
   http_header_interceptor_map_[http_header] = interceptor_info;
 }
 
+void ResourceDispatcherHostImpl::ReprioritizeRequest(
+    net::URLRequest* request,
+    net::RequestPriority priority) {
+  scheduler_->ReprioritizeRequest(request, priority);
+}
+
 void ResourceDispatcherHostImpl::Shutdown() {
   DCHECK(main_thread_task_runner_->BelongsToCurrentThread());
   io_thread_task_runner_->PostTask(