Avoid doing concurrent DNS resolves of the same hostname

net/proxy/proxy_resolver_perftest.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/perftimer.h"
 #include "net/proxy/proxy_resolver_v8.h"
 #include "net/url_request/url_request_unittest.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 #if defined(OS_WIN)
@@ skipping 167 matching lines @@
 }
 #elif defined(OS_MACOSX)
 TEST(ProxyResolverPerfTest, ProxyResolverMac) {
   net::ProxyResolverMac resolver;
   PacPerfSuiteRunner runner(&resolver, "ProxyResolverMac");
   runner.RunAllTests();
 }
 #endif
 
 TEST(ProxyResolverPerfTest, ProxyResolverV8) {
-  net::ProxyResolverV8 resolver;
+  net::HostResolver host_resolver;
+
+  net::ProxyResolverV8::JSBindings* js_bindings =
+      net::ProxyResolverV8::CreateDefaultBindings(&host_resolver, NULL);
+
+  net::ProxyResolverV8 resolver(js_bindings);
   PacPerfSuiteRunner runner(&resolver, "ProxyResolverV8");
   runner.RunAllTests();
 }