Lazily initialize the v8::Isolate used by ProxyResolverV8 (in the browser process).

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 "base/command_line.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/threading/thread.h"
@@ skipping 86 matching lines @@
 
   // TODO(michaeln): Remove ScopedTracker below once crbug.com/454983 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "454983 ProxyServiceFactory::CreateProxyService"));
 
 #if defined(OS_IOS)
   bool use_v8 = false;
 #else
   bool use_v8 = !command_line.HasSwitch(switches::kWinHttpProxyResolver);
-  if (use_v8 && command_line.HasSwitch(switches::kSingleProcess)) {
-    // See the note about V8 multithreading in net/proxy/proxy_resolver_v8.h
-    // to understand why we have this limitation.
-    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).
     int n;
     if (base::StringToInt(s, &n) && n > 0) {
       num_pac_threads = static_cast<size_t>(n);
     } else {
       LOG(ERROR) << "Invalid switch for number of PAC threads: " << s;
     }
   }
 
   net::ProxyService* proxy_service = NULL;
   if (use_v8) {
 #if defined(OS_IOS)
     NOTREACHED();
 #else
-    net::ProxyResolverV8::EnsureIsolateCreated();
-
     net::DhcpProxyScriptFetcher* dhcp_proxy_script_fetcher;
 #if defined(OS_CHROMEOS)
     dhcp_proxy_script_fetcher =
         new chromeos::DhcpProxyScriptFetcherChromeos(context);
 #else
     net::DhcpProxyScriptFetcherFactory dhcp_factory;
     dhcp_proxy_script_fetcher = dhcp_factory.Create(context);
 #endif
 
     proxy_service = net::CreateProxyServiceUsingV8ProxyResolver(
         proxy_config_service,
         new net::ProxyScriptFetcherImpl(context),
         dhcp_proxy_script_fetcher,
         context->host_resolver(),
         net_log,
         network_delegate);
 #endif  // defined(OS_IOS)
   } else {
     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;
 }