Move ProxyConfigService construction onto the IO thread.

net/proxy/proxy_service.cc

Index: net/proxy/proxy_service.cc
diff --git a/net/proxy/proxy_service.cc b/net/proxy/proxy_service.cc
index 9989b8221cdc09944ce3e14622d3d088851b6f7e..6e6d6e37e5b72545237e4cf5c604060c44817ab1 100644
--- a/net/proxy/proxy_service.cc
+++ b/net/proxy/proxy_service.cc
@@ -1318,47 +1318,37 @@ void ProxyService::ForceReloadProxyConfig() {
   ApplyProxyConfigIfAvailable();
 }
 
+void ProxyService::StartTearDown() {
+  config_service_->StartTearDown();
+}
+
 // static
 ProxyConfigService* ProxyService::CreateSystemProxyConfigService(
-    base::SingleThreadTaskRunner* io_thread_task_runner,
+    base::SingleThreadTaskRunner* glib_thread_task_runner,
     MessageLoop* file_loop) {
 #if defined(OS_WIN)
   return new ProxyConfigServiceWin();
 #elif defined(OS_IOS)
   return new ProxyConfigServiceIOS();
 #elif defined(OS_MACOSX)
-  return new ProxyConfigServiceMac(io_thread_task_runner);
+  return new ProxyConfigServiceMac(
+      MessageLoopForIO::current()->message_loop_proxy());
 #elif defined(OS_CHROMEOS)
   LOG(ERROR) << "ProxyConfigService for ChromeOS should be created in "
              << "profile_io_data.cc::CreateProxyConfigService and this should "
              << "be used only for examples.";
   return new UnsetProxyConfigService;
 #elif defined(OS_LINUX)
-  ProxyConfigServiceLinux* linux_config_service =
-      new ProxyConfigServiceLinux();
-
-  // Assume we got called on the thread that runs the default glib
-  // main loop, so the current thread is where we should be running
-  // gconf calls from.
-  scoped_refptr<base::SingleThreadTaskRunner> glib_thread_task_runner =
-      base::ThreadTaskRunnerHandle::Get();
-
   // The file loop should be a MessageLoopForIO on Linux.
   DCHECK_EQ(MessageLoop::TYPE_IO, file_loop->type());
-
-  // Synchronously fetch the current proxy config (since we are
-  // running on glib_default_loop). Additionally register for
-  // notifications (delivered in either |glib_default_loop| or
-  // |file_loop|) to keep us updated when the proxy config changes.
-  linux_config_service->SetupAndFetchInitialConfig(
-      glib_thread_task_runner, io_thread_task_runner,
+  return new ProxyConfigServiceLinux(
+      glib_thread_task_runner,
+      MessageLoopForIO::current()->message_loop_proxy(),
       static_cast<MessageLoopForIO*>(file_loop));
-
-  return linux_config_service;
 #elif defined(OS_ANDROID)
   return new ProxyConfigServiceAndroid(
-      io_thread_task_runner,
-      MessageLoopForUI::current()->message_loop_proxy());
+      glib_thread_task_runner,
+      MessageLoopForIO::current()->message_loop_proxy());
 #else
   LOG(WARNING) << "Failed to choose a system proxy settings fetcher "
                   "for this platform.";