PairingAuthenticator implementation and plumbing.

remoting/host/remoting_me2me_host.cc

Index: remoting/host/remoting_me2me_host.cc
diff --git a/remoting/host/remoting_me2me_host.cc b/remoting/host/remoting_me2me_host.cc
index 6ee42b9ff8d15d1e8cc16b47949b21f3d2e84cd5..f6e4ee9459930798b988d7b505decd10df9d1d34 100644
--- a/remoting/host/remoting_me2me_host.cc
+++ b/remoting/host/remoting_me2me_host.cc
@@ -67,6 +67,7 @@
 #include "remoting/host/usage_stats_consent.h"
 #include "remoting/jingle_glue/xmpp_signal_strategy.h"
 #include "remoting/protocol/me2me_host_authenticator_factory.h"
+#include "remoting/protocol/pairing_registry.h"
 
 #if defined(OS_POSIX)
 #include <signal.h>
@@ -465,9 +466,13 @@ void HostProcess::CreateAuthenticatorFactory() {
   }
   scoped_ptr<protocol::AuthenticatorFactory> factory;
 
+  // TODO(jamiewalch): Add a proper pairing registry here once all the code
+  // is committed.
+  scoped_refptr<remoting::protocol::PairingRegistry> pairing_registry;
+
   if (token_url_.is_empty() && token_validation_url_.is_empty()) {
     factory = protocol::Me2MeHostAuthenticatorFactory::CreateWithSharedSecret(
-        local_certificate, key_pair_, host_secret_hash_);
+        local_certificate, key_pair_, host_secret_hash_, pairing_registry);
   } else if (token_url_.is_valid() && token_validation_url_.is_valid()) {
     scoped_ptr<protocol::ThirdPartyHostAuthenticator::TokenValidatorFactory>
         token_validator_factory(new TokenValidatorFactoryImpl(