[remoting android] Remove host It2Me implementation.

remoting/host/pairing_registry_delegate_android.cc

Index: remoting/host/pairing_registry_delegate_android.cc
diff --git a/remoting/host/pairing_registry_delegate_android.cc b/remoting/host/pairing_registry_delegate_android.cc
deleted file mode 100644
index ce5e774ef88031b321a8902c3039db8e8bf76c88..0000000000000000000000000000000000000000
--- a/remoting/host/pairing_registry_delegate_android.cc
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "remoting/host/pairing_registry_delegate.h"
-
-namespace remoting {
-
-using protocol::PairingRegistry;
-
-std::unique_ptr<PairingRegistry::Delegate> CreatePairingRegistryDelegate() {
-  return nullptr;
-}
-
-}  // namespace remoting