Revert 148418 - Always use chromium threads for IO in remoting host

remoting/host/simple_host_process.cc

Index: remoting/host/simple_host_process.cc
===================================================================
--- remoting/host/simple_host_process.cc	(revision 148577)
+++ remoting/host/simple_host_process.cc	(working copy)
@@ -217,9 +217,9 @@
   }
 
   void StartHost() {
-    signal_strategy_.reset(new XmppSignalStrategy(
-        context_.url_request_context_getter(),
-        xmpp_login_, xmpp_auth_token_, xmpp_auth_service_));
+    signal_strategy_.reset(
+        new XmppSignalStrategy(context_.jingle_thread(), xmpp_login_,
+                               xmpp_auth_token_, xmpp_auth_service_));
     signaling_connector_.reset(new SignalingConnector(
         signal_strategy_.get(),
         base::Bind(&SimpleHost::OnAuthFailed, base::Unretained(this))));