Add a Dns preresolve interface in //content

chrome/browser/chromeos/login/helper.cc

Index: chrome/browser/chromeos/login/helper.cc
diff --git a/chrome/browser/chromeos/login/helper.cc b/chrome/browser/chromeos/login/helper.cc
index 688b1d8331dde98f7a52fa46292d69fc9204c951..c80616b564be914b959b73718fdeffa340bf4183 100644
--- a/chrome/browser/chromeos/login/helper.cc
+++ b/chrome/browser/chromeos/login/helper.cc
@@ -22,6 +22,7 @@
 #include "chromeos/network/network_state_handler.h"
 #include "chromeos/network/network_util.h"
 #include "components/guest_view/browser/guest_view_manager.h"
+#include "content/public/browser/resource_context.h"
 #include "content/public/browser/storage_partition.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/browser/guest_view/web_view/web_view_guest.h"
@@ -249,6 +250,10 @@ net::URLRequestContextGetter* GetSigninContext() {
   return ProfileHelper::GetSigninProfile()->GetRequestContext();
 }
 
+content::ResourceContext* GetSigninResourceContext() {
+  return ProfileHelper::GetSigninProfile()->GetResourceContext();
+}
+
 }  // namespace login
 
 }  // namespace chromeos