Remove prerender cookie store, part 4.

mojo/services/network/url_loader_impl.cc

Index: mojo/services/network/url_loader_impl.cc
diff --git a/mojo/services/network/url_loader_impl.cc b/mojo/services/network/url_loader_impl.cc
index d159712a3175e0250d7290c8c077f854673f6d69..693502f2f912c265dd9f7115eb6546f15ca5142f 100644
--- a/mojo/services/network/url_loader_impl.cc
+++ b/mojo/services/network/url_loader_impl.cc
@@ -119,7 +119,7 @@ void URLLoaderImpl::Start(URLRequestPtr request,
   }
 
   url_request_ = context_->url_request_context()->CreateRequest(
-      GURL(request->url), net::DEFAULT_PRIORITY, this, nullptr);
+      GURL(request->url), net::DEFAULT_PRIORITY, this);
   url_request_->set_method(request->method);
   if (request->headers) {
     net::HttpRequestHeaders headers;