Change BrowserThreadDelegate to run Init() async.

chrome/browser/io_thread.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/io_thread.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 446 matching lines @@
 
 net::URLRequestContextGetter* IOThread::system_url_request_context_getter() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (!system_url_request_context_getter_.get()) {
     InitSystemRequestContext();
   }
   return system_url_request_context_getter_.get();
 }
 
 void IOThread::Init() {
-  TRACE_EVENT0("startup", "IOThread::Init");
+  // Prefer to use InitAsync unless you need initialization to block
+  // the UI thread
+}
+
+void IOThread::InitAsync() {
+  TRACE_EVENT0("startup", "IOThread::InitAsync");
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
 #if defined(USE_NSS) || defined(OS_IOS)
   net::SetMessageLoopForNSSHttpIO();
 #endif
 
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
   DCHECK(!globals_);
   globals_ = new Globals;
@@ skipping 40 matching lines @@
   globals_->system_server_bound_cert_service.reset(
       new net::ServerBoundCertService(
           new net::DefaultServerBoundCertStore(NULL),
           base::WorkerPool::GetTaskRunner(true)));
   globals_->dns_probe_service.reset(new chrome_browser_net::DnsProbeService());
   globals_->load_time_stats.reset(new chrome_browser_net::LoadTimeStats());
   globals_->host_mapping_rules.reset(new net::HostMappingRules());
   globals_->http_user_agent_settings.reset(
       new BasicHttpUserAgentSettings(std::string()));
   if (command_line.HasSwitch(switches::kHostRules)) {
-    TRACE_EVENT_BEGIN0("startup", "IOThread::Init:SetRulesFromString");
+    TRACE_EVENT_BEGIN0("startup", "IOThread::InitAsync:SetRulesFromString");
     globals_->host_mapping_rules->SetRulesFromString(
         command_line.GetSwitchValueASCII(switches::kHostRules));
-    TRACE_EVENT_END0("startup", "IOThread::Init:SetRulesFromString");
+    TRACE_EVENT_END0("startup", "IOThread::InitAsync:SetRulesFromString");
   }
   if (command_line.HasSwitch(switches::kIgnoreCertificateErrors))
     globals_->ignore_certificate_errors = true;
   if (command_line.HasSwitch(switches::kTestingFixedHttpPort)) {
     globals_->testing_fixed_http_port =
         GetSwitchValueAsInt(command_line, switches::kTestingFixedHttpPort);
   }
   if (command_line.HasSwitch(switches::kTestingFixedHttpsPort)) {
     globals_->testing_fixed_https_port =
         GetSwitchValueAsInt(command_line, switches::kTestingFixedHttpsPort);
@@ skipping 15 matching lines @@
     globals_->enable_user_alternate_protocol_ports = true;
   }
   InitializeNetworkOptions(command_line);
 
   net::HttpNetworkSession::Params session_params;
   InitializeNetworkSessionParams(&session_params);
   session_params.net_log = net_log_;
   session_params.proxy_service =
       globals_->proxy_script_fetcher_proxy_service.get();
 
-  TRACE_EVENT_BEGIN0("startup", "IOThread::Init:HttpNetworkSession");
+  TRACE_EVENT_BEGIN0("startup", "IOThread::InitAsync:HttpNetworkSession");
   scoped_refptr<net::HttpNetworkSession> network_session(
       new net::HttpNetworkSession(session_params));
   globals_->proxy_script_fetcher_http_transaction_factory
       .reset(new net::HttpNetworkLayer(network_session.get()));
-  TRACE_EVENT_END0("startup", "IOThread::Init:HttpNetworkSession");
+  TRACE_EVENT_END0("startup", "IOThread::InitAsync:HttpNetworkSession");
   scoped_ptr<net::URLRequestJobFactoryImpl> job_factory(
       new net::URLRequestJobFactoryImpl());
   job_factory->SetProtocolHandler(chrome::kDataScheme,
                                   new net::DataProtocolHandler());
   job_factory->SetProtocolHandler(chrome::kFileScheme,
                                   new net::FileProtocolHandler());
 #if !defined(DISABLE_FTP_SUPPORT)
   globals_->proxy_script_fetcher_ftp_transaction_factory.reset(
       new net::FtpNetworkLayer(globals_->host_resolver.get()));
   job_factory->SetProtocolHandler(
@@ skipping 383 matching lines @@
   if (command_line.HasSwitch(switches::kDisableQuic))
     return false;
 
   if (command_line.HasSwitch(switches::kEnableQuic) ||
       command_line.HasSwitch(switches::kEnableQuicHttps)) {
     return true;
   }
 
   return quic_trial_group == kQuicFieldTrialEnabledGroupName;
 }