Stop login prompt from showing for prefetches

chrome/browser/renderer_host/resource_dispatcher_host.cc

Index: chrome/browser/renderer_host/resource_dispatcher_host.cc
diff --git a/chrome/browser/renderer_host/resource_dispatcher_host.cc b/chrome/browser/renderer_host/resource_dispatcher_host.cc
index ef9ec9c4e36e8d16eb3f8fdbee50aeda6191b61b..3d9221a3d9799d6a2df56df0967a4a49c02de0bc 100644
--- a/chrome/browser/renderer_host/resource_dispatcher_host.cc
+++ b/chrome/browser/renderer_host/resource_dispatcher_host.cc
@@ -1040,6 +1040,10 @@ void ResourceDispatcherHost::OnReceivedRedirect(net::URLRequest* request,
 void ResourceDispatcherHost::OnAuthRequired(
     net::URLRequest* request,
     net::AuthChallengeInfo* auth_info) {
+  if (request->load_flags() & net::LOAD_PREFETCH) {
+    request->CancelAuth();
+    return;
+  }
   // Create a login dialog on the UI thread to get authentication data,
   // or pull from cache and continue on the IO thread.
   // TODO(mpcomplete): We should block the parent tab while waiting for