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

remoting/host/setup/oauth_helper.h

-// 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_SETUP_OAUTH_HELPER_H
-#define REMOTING_HOST_SETUP_OAUTH_HELPER_H
-
-#include <string>
-
-namespace remoting {
-
-// Gets the OAuth scope of the host's refresh token.
-std::string GetOauthScope();
-
-// Gets the default redirect URL for the OAuth dance.
-std::string GetDefaultOauthRedirectUrl();
-
-// Gets a URL at which the OAuth dance starts.
-std::string GetOauthStartUrl(const std::string& redirect_url);
-
-// Returns the OAuth authorization code embedded in a URL, or the empty string
-// if there is no such code.
-// To get an OAuth authorization code, (i) start a browser, (ii) navigate it
-// to |GetOauthStartUrl()|, (iii) ask the user to sign on to their account,
-// and grant the requested permissions, (iv) monitor the URLs that the browser
-// shows, passing each one to |GetOauthCodeInUrl()|, until that function returns
-// a non-empty string. That string is the authorization code.
-std::string GetOauthCodeInUrl(const std::string& url,
-                              const std::string& redirect_url);
-
-}  // namespace remoting
-
-#endif  // REMOTING_HOST_SETUP_OAUTH_HELPER_H