Implemented local login check for PAM (only enabled on Linux for now).

remoting/host/pam_authorization_factory_posix.h

Index: remoting/host/pam_authorization_factory_posix.h
diff --git a/remoting/host/pam_authorization_factory_posix.h b/remoting/host/pam_authorization_factory_posix.h
new file mode 100644
index 0000000000000000000000000000000000000000..7219698b58e6a9c011f18fe7215a42283aad085f
--- /dev/null
+++ b/remoting/host/pam_authorization_factory_posix.h
@@ -0,0 +1,34 @@
+// Copyright (c) 2012 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.
+
+#ifndef REMOTING_HOST_PAM_AUTHORIZATION_FACTORY_POSIX_H_
+#define REMOTING_HOST_PAM_AUTHORIZATION_FACTORY_POSIX_H_
+
+#include "remoting/protocol/authenticator.h"
+
+#include "base/memory/scoped_ptr.h"
+
+// PamAuthorizationFactory abuses the AuthenticatorFactory interface to apply
+// PAM-based authorization on top of some underlying authentication scheme.
+
+namespace remoting {
+
+class PamAuthorizationFactory : public protocol::AuthenticatorFactory {
+ public:
+  PamAuthorizationFactory(
+      scoped_ptr<protocol::AuthenticatorFactory> underlying);
+  virtual ~PamAuthorizationFactory();
+
+  virtual scoped_ptr<protocol::Authenticator> CreateAuthenticator(
+      const std::string& local_jid,
+      const std::string& remote_jid,
+      const buzz::XmlElement* first_message) OVERRIDE;
+
+ private:
+  scoped_ptr<protocol::AuthenticatorFactory> underlying_;
+};
+
+}  // namespace remoting
+
+#endif