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

remoting/host/oauth_token_getter.h

-// Copyright 2014 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_OAUTH_TOKEN_GETTER_H_
-#define REMOTING_HOST_OAUTH_TOKEN_GETTER_H_
-
-#include <string>
-
-#include "base/callback.h"
-#include "base/macros.h"
-
-namespace remoting {
-
-// OAuthTokenGetter caches OAuth access tokens and refreshes them as needed.
-class OAuthTokenGetter {
- public:
-  // Status of the refresh token attempt.
-  enum Status {
-    // Success, credentials in user_email/access_token.
-    SUCCESS,
-    // Network failure (caller may retry).
-    NETWORK_ERROR,
-    // Authentication failure (permanent).
-    AUTH_ERROR,
-  };
-
-  typedef base::Callback<void(Status status,
-                              const std::string& user_email,
-                              const std::string& access_token)> TokenCallback;
-
-  // This structure contains information required to perform
-  // authentication to OAuth2.
-  struct OAuthCredentials {
-    // |is_service_account| should be True if the OAuth refresh token is for a
-    // service account, False for a user account, to allow the correct client-ID
-    // to be used.
-    OAuthCredentials(const std::string& login,
-                     const std::string& refresh_token,
-                     bool is_service_account);
-
-    // The user's account name (i.e. their email address).
-    std::string login;
-
-    // Token delegating authority to us to act as the user.
-    std::string refresh_token;
-
-    // Whether these credentials belong to a service account.
-    bool is_service_account;
-  };
-
-  OAuthTokenGetter() {}
-  virtual ~OAuthTokenGetter() {}
-
-  // Call |on_access_token| with an access token, or the failure status.
-  virtual void CallWithToken(
-      const OAuthTokenGetter::TokenCallback& on_access_token) = 0;
-
-  // Invalidates the cache, so the next CallWithToken() will get a fresh access
-  // token.
-  virtual void InvalidateCache() = 0;
-
-  DISALLOW_COPY_AND_ASSIGN(OAuthTokenGetter);
-};
-
-}  // namespace remoting
-
-#endif  // REMOTING_HOST_OAUTH_TOKEN_GETTER_H_