Declarative resource hints go through mojo IPC to //content

content/browser/loader/resource_hints_impl.cc

Index: content/browser/loader/resource_hints_impl.cc
diff --git a/content/browser/loader/resource_hints_impl.cc b/content/browser/loader/resource_hints_impl.cc
index e6f18c00346c3c0139c406a7862fe7b0ea14131c..a8b9558698ee0fb8aa70e43084d99b1865c44e5b 100644
--- a/content/browser/loader/resource_hints_impl.cc
+++ b/content/browser/loader/resource_hints_impl.cc
@@ -29,7 +29,13 @@ void OnResolveComplete(net::SingleRequestHostResolver* request,
                        int result) {
   // Plumb the resolution result into the callback if future consumers want
   // that information.
-  callback.Run(result);
+  if (!callback.is_null())
+    callback.Run(result);
+}
+
+bool ValidUrl(const GURL& url) {
+  return url.is_valid() && url.has_host() && url.has_scheme() &&
+         url.SchemeIsHTTPOrHTTPS();
 }
 
 }  // namespace
@@ -43,6 +49,9 @@ void PreconnectUrl(content::ResourceContext* resource_context,
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(resource_context);
 
+  if (!ValidUrl(url))
+    return;
+
   net::URLRequestContext* context = resource_context->GetRequestContext();
   net::HttpTransactionFactory* factory = context->http_transaction_factory();
   net::HttpNetworkSession* session = factory->GetSession();
@@ -81,6 +90,9 @@ int PreresolveUrl(content::ResourceContext* resource_context,
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(resource_context);
 
+  if (!ValidUrl(url))
+    return net::ERR_INVALID_URL;
+
   net::AddressList* addresses = new net::AddressList;
   net::SingleRequestHostResolver* resolver =
       new net::SingleRequestHostResolver(resource_context->GetHostResolver());