Always create URLRequestContextGetter in ChromotingHostContext.

remoting/host/chromoting_host_context.cc

Index: remoting/host/chromoting_host_context.cc
diff --git a/remoting/host/chromoting_host_context.cc b/remoting/host/chromoting_host_context.cc
index 57571a99f18872703b391889446168a77d125898..1eaa4540cb8fe85ed1ce28cc2d1216bface4ff86 100644
--- a/remoting/host/chromoting_host_context.cc
+++ b/remoting/host/chromoting_host_context.cc
@@ -37,13 +37,9 @@ bool ChromotingHostContext::Start() {
   if (!started)
     return false;
 
-  // net::ProxyService::CreateSystemProxyConfigService requires a UI thread.
-  // TODO(jamiewalch): Clean up this dependency.
-  MessageLoop* loop = MessageLoop::current();
-  if (loop && loop->type() == MessageLoop::TYPE_UI) {
-    url_request_context_getter_ = new URLRequestContextGetter(
-        io_thread_.message_loop(), file_thread_.message_loop());
-  }
+  url_request_context_getter_ = new URLRequestContextGetter(
+      ui_message_loop_, io_thread_.message_loop(),
+      static_cast<MessageLoopForIO*>(file_thread_.message_loop()));
   return true;
 }