Always use chromium threads for IO in remoting host

remoting/host/simple_host_process.cc

Index: remoting/host/simple_host_process.cc
diff --git a/remoting/host/simple_host_process.cc b/remoting/host/simple_host_process.cc
index a181f7b56e6ef57a331295427b209b00d080ed1c..63dc305e5f1ad780e3efd66257703c62722c53e2 100644
--- a/remoting/host/simple_host_process.cc
+++ b/remoting/host/simple_host_process.cc
@@ -217,9 +217,9 @@ class SimpleHost : public HeartbeatSender::Listener {
   }
 
   void StartHost() {
-    signal_strategy_.reset(
-        new XmppSignalStrategy(context_.jingle_thread(), xmpp_login_,
-                               xmpp_auth_token_, xmpp_auth_service_));
+    signal_strategy_.reset(new XmppSignalStrategy(
+        context_.url_request_context_getter(),
+        xmpp_login_, xmpp_auth_token_, xmpp_auth_service_));
     signaling_connector_.reset(new SignalingConnector(
         signal_strategy_.get(),
         base::Bind(&SimpleHost::OnAuthFailed, base::Unretained(this))));