Make the v8 Isolate used in the proxy resolver explicit.

net/proxy/proxy_resolver_perftest.cc

 // Copyright (c) 2012 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/base_paths.h"
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/perftimer.h"
 #include "base/string_util.h"
@@ skipping 197 matching lines @@
     CHECK(false);
     return false;
   }
 
   virtual void OnError(int line_number, const string16& message) OVERRIDE {
     CHECK(false);
   }
 };
 
 TEST(ProxyResolverPerfTest, ProxyResolverV8) {
+  // This has to be done on the main thread.
+  net::ProxyResolverV8::RememberDefaultIsolate();
+
   MockJSBindings js_bindings;
   net::ProxyResolverV8 resolver;
   resolver.set_js_bindings(&js_bindings);
   PacPerfSuiteRunner runner(&resolver, "ProxyResolverV8");
   runner.RunAllTests();
 }
-