Enable setting deferral state on ResourceDispatcher at request start

content/child/web_url_loader_impl.cc

Index: content/child/web_url_loader_impl.cc
diff --git a/content/child/web_url_loader_impl.cc b/content/child/web_url_loader_impl.cc
index 41daeb0975151871e7c97f6044ec1b382bf124c8..2a8a3563cfbae4528cb6cd53d3305aba4b9f84f9 100644
--- a/content/child/web_url_loader_impl.cc
+++ b/content/child/web_url_loader_impl.cc
@@ -555,6 +555,7 @@ void WebURLLoaderImpl::Context::Start(const WebURLRequest& request,
   }
 
   if (sync_load_response) {
+    DCHECK(defers_loading_ == NOT_DEFERRING);
     resource_dispatcher_->StartSync(
         request_info, request_body.get(), sync_load_response);
     return;
@@ -563,6 +564,9 @@ void WebURLLoaderImpl::Context::Start(const WebURLRequest& request,
   request_id_ = resource_dispatcher_->StartAsync(
       request_info, request_body.get(),
       base::WrapUnique(new WebURLLoaderImpl::RequestPeerImpl(this)));
+
+  if (defers_loading_ != NOT_DEFERRING)
+    resource_dispatcher_->SetDefersLoading(request_id_, true);
 }
 
 void WebURLLoaderImpl::Context::SetWebTaskRunner(