Re-disable V8-based proxy resolving with the --single-process command line is set.

chrome/browser/net/proxy_service_factory.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 "chrome/browser/net/proxy_service_factory.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 86 matching lines @@
     net::URLRequestContext* context,
     net::NetworkDelegate* network_delegate,
     net::ProxyConfigService* proxy_config_service,
     const base::CommandLine& command_line,
     bool quick_check_enabled) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 #if defined(OS_IOS)
   bool use_v8 = false;
 #else
   bool use_v8 = !command_line.HasSwitch(switches::kWinHttpProxyResolver);
+  // TODO(eroman): Figure out why this doesn't work in single-process mode.
+  // Should be possible now that a private isolate is used.
+  // http://crbug.com/474654
+  if (use_v8 && command_line.HasSwitch(switches::kSingleProcess)) {
+    LOG(ERROR) << "Cannot use V8 Proxy resolver in single process mode.";
+    use_v8 = false;  // Fallback to non-v8 implementation.
+  }
 #endif  // defined(OS_IOS)
 
   size_t num_pac_threads = 0u;  // Use default number of threads.
 
   // Check the command line for an override on the number of proxy resolver
   // threads to use.
   if (command_line.HasSwitch(switches::kNumPacThreads)) {
     std::string s = command_line.GetSwitchValueASCII(switches::kNumPacThreads);
 
     // Parse the switch (it should be a positive integer formatted as decimal).
@@ skipping 45 matching lines @@
     proxy_service = net::ProxyService::CreateUsingSystemProxyResolver(
         proxy_config_service,
         num_pac_threads,
         net_log);
   }
 
   proxy_service->set_quick_check_enabled(quick_check_enabled);
 
   return proxy_service;
 }