Moving oauth code from host to base to allow code sharing between host and client.

remoting/host/setup/oauth_client.h

-// Copyright 2013 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_SETUP_OAUTH_CLIENT_H_
-#define REMOTING_HOST_SETUP_OAUTH_CLIENT_H_
-
-#include <string>
-
-#include "base/callback.h"
-
-namespace gaia {
-struct OAuthClientInfo;
-}
-
-namespace remoting {
-
-class OAuthClient {
- public:
-  // Called when GetCredentialsFromAuthCode is completed, with the |user_email|
-  // and |refresh_token| that correspond to the given |auth_code|, or with empty
-  // strings on error.
-  typedef base::Callback<void(
-      const std::string& user_email,
-      const std::string& refresh_token)> CompletionCallback;
-
-  virtual ~OAuthClient() {}
-
-  // Redeems |auth_code| using |oauth_client_info| to obtain
-  // |refresh_token| and |access_token|, then, if |need_user_email| is
-  // true, uses the userinfo endpoint to obtain |user_email|.  Calls
-  // CompletionCallback with |user_email| and |refresh_token| when
-  // done, or with empty strings on error.  If a request is received
-  // while another one is being processed, it is enqueued and
-  // processed after the first one is finished.
-  virtual void GetCredentialsFromAuthCode(
-      const gaia::OAuthClientInfo& oauth_client_info,
-      const std::string& auth_code,
-      bool need_user_email,
-      CompletionCallback on_done) = 0;
-};
-
-}  // namespace remoting
-
-#endif  // REMOTING_HOST_SETUP_OAUTH_CLIENT_H_