Avoid doing concurrent DNS resolves of the same hostname

net/http/http_network_transaction_unittest.cc

Index: net/http/http_network_transaction_unittest.cc
===================================================================
--- net/http/http_network_transaction_unittest.cc	(revision 18213)
+++ net/http/http_network_transaction_unittest.cc	(working copy)
@@ -41,6 +41,7 @@
   explicit SessionDependencies(ProxyService* proxy_service)
       : proxy_service(proxy_service) {}
 
+  HostResolver host_resolver;
   scoped_ptr<ProxyService> proxy_service;
   MockClientSocketFactory socket_factory;
 };
@@ -53,7 +54,8 @@
 
 
 HttpNetworkSession* CreateSession(SessionDependencies* session_deps) {
-  return new HttpNetworkSession(session_deps->proxy_service.get(),
+  return new HttpNetworkSession(&session_deps->host_resolver,
+                                session_deps->proxy_service.get(),
                                 &session_deps->socket_factory);
 }