Remove ChromotingHostContext from DnsBlackholeChecker.

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 6caacacb0b9a0a1631e934a802675c76a3885005..a8321dbc302850e691d45e38feeba7f0a262ca84 100644
--- a/remoting/host/simple_host_process.cc
+++ b/remoting/host/simple_host_process.cc
@@ -253,7 +253,8 @@ class SimpleHost : public HeartbeatSender::Listener {
         context_.url_request_context_getter(),
         xmpp_login_, xmpp_auth_token_, xmpp_auth_service_));
     scoped_ptr<DnsBlackholeChecker> dns_blackhole_checker(
-        new DnsBlackholeChecker(&context_, kDefaultHostTalkGadgetPrefix));
+        new DnsBlackholeChecker(context_.url_request_context_getter(),
+                                kDefaultHostTalkGadgetPrefix));
     signaling_connector_.reset(new SignalingConnector(
         signal_strategy_.get(), &context_, dns_blackhole_checker.Pass(),
         base::Bind(&SimpleHost::OnAuthFailed, base::Unretained(this))));