Add a field trial to enable out-of-process V8 pac.

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/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/threading/thread.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/io_thread.h"
 #include "chrome/browser/net/pref_proxy_config_tracker_impl.h"
 #include "chrome/common/chrome_switches.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/log/net_log.h"
 #include "net/proxy/dhcp_proxy_script_fetcher_factory.h"
 #include "net/proxy/proxy_config_service.h"
@@ skipping 11 matching lines @@
 #include "net/proxy/proxy_resolver_v8.h"
 #endif
 
 #if !defined(OS_IOS) && !defined(OS_ANDROID)
 #include "chrome/browser/net/utility_process_mojo_proxy_resolver_factory.h"
 #include "net/proxy/proxy_service_mojo.h"
 #endif
 
 using content::BrowserThread;
 
+namespace {
+
+#if !defined(OS_ANDROID)
+bool EnableOutOfProcessV8Pac(const base::CommandLine& command_line) {
+  const std::string group_name =
+      base::FieldTrialList::FindFullName("OutOfProcessPac");
+
+  if (command_line.HasSwitch(switches::kDisableOutOfProcessPac))
+    return false;
+  if (command_line.HasSwitch(switches::kV8PacMojoOutOfProcess))
+    return true;
+  return group_name == "Enabled";
+}
+#endif  // !defined(OS_ANDROID)
+
+}  // namespace
+
 // static
 net::ProxyConfigService* ProxyServiceFactory::CreateProxyConfigService(
     PrefProxyConfigTracker* tracker) {
   // The linux gconf-based proxy settings getter relies on being initialized
   // from the UI thread.
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   scoped_ptr<net::ProxyConfigService> base_service;
 
 #if !defined(OS_CHROMEOS)
@@ skipping 45 matching lines @@
     net::NetLog* net_log,
     net::URLRequestContext* context,
     net::NetworkDelegate* network_delegate,
     net::ProxyConfigService* proxy_config_service,
     const base::CommandLine& command_line,
     bool quick_check_enabled) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 #if defined(OS_IOS)
   bool use_v8 = false;
 #else
   bool use_v8 = !command_line.HasSwitch(switches::kWinHttpProxyResolver);

[eroman, 2015/05/12 05:21:40]

I think the presence of this flag should also override out-of-process PAC. Since
if PAC goes out of process, there will not be support for using the system proxy
resolver (which is what kWinHttpProxyResolver actually means)

[Anand Mistry (off Chromium), 2015/05/12 07:16:04]

Isn't that already the case? If this flag is set, use_v8 == false, and the code
path that creates the out-of-process resolver isn't hit and the system resolver
is created instead.

[eroman, 2015/05/14 22:31:29]

right you are!

   // 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.
@@ skipping 20 matching lines @@
     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
 
 #if !defined(OS_ANDROID)
-    if (command_line.HasSwitch(switches::kV8PacMojoOutOfProcess)) {
+    // In-process Mojo PAC can only be set on the command line, so it's presence
+    // should override other options.
+    if (command_line.HasSwitch(switches::kV8PacMojoInProcess)) {
+      proxy_service = net::CreateProxyServiceUsingMojoInProcess(
+          proxy_config_service, new net::ProxyScriptFetcherImpl(context),
+          dhcp_proxy_script_fetcher, context->host_resolver(), net_log,
+          network_delegate);
+    }
+
+    if (!proxy_service && EnableOutOfProcessV8Pac(command_line)) {

[eroman, 2015/05/12 05:21:41]

rather than !proxy_service, can you do an "else if" ?

[Anand Mistry (off Chromium), 2015/05/12 07:16:04]

Done.

       proxy_service = net::CreateProxyServiceUsingMojoFactory(
           UtilityProcessMojoProxyResolverFactory::GetInstance(),
           proxy_config_service, new net::ProxyScriptFetcherImpl(context),
           dhcp_proxy_script_fetcher, context->host_resolver(), net_log,
           network_delegate);
-    } else if (command_line.HasSwitch(switches::kV8PacMojoInProcess)) {
-      proxy_service = net::CreateProxyServiceUsingMojoInProcess(
-          proxy_config_service, new net::ProxyScriptFetcherImpl(context),
-          dhcp_proxy_script_fetcher, context->host_resolver(), net_log,
-          network_delegate);
     }
 #endif  // !defined(OS_ANDROID)
 
     if (!proxy_service) {
       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;
 }