Implement oauth token external handler checking.

chrome/browser/chromeos/login/signin/token_handler_util.h

+// Copyright 2015 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 CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_TOKEN_HANDLER_UTIL_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_TOKEN_HANDLER_UTIL_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/containers/scoped_ptr_hash_map.h"
+#include "base/memory/weak_ptr.h"
+#include "components/user_manager/user_id.h"
+#include "google_apis/gaia/gaia_oauth_client.h"
+
+namespace base {
+class DictionaryValue;
+}
+
+namespace user_manager {
+class UserManager;
+}
+
+// This class is responsible for operations with External Token Handle.
+// Handle is an extra token associated with OAuth refresh token that have
+// exactly same lifetime. It is not secure, and it's only purpose is checking
+// validity of corresponding refresh token in the insecure environment.
+class TokenHandlerUtil {
+ public:
+  explicit TokenHandlerUtil(user_manager::UserManager* user_manager);
+  ~TokenHandlerUtil();
+
+  enum TokenHandleStatus { VALID, INVALID, UNKNOWN };
+
+  typedef base::Callback<void(const user_manager::UserID&, TokenHandleStatus)>
+      TokenValidationCallback;
+
+  // Returns true if UserManager has token handle associated with |user_id|.
+  bool HasToken(const user_manager::UserID& user_id);
+  // Removes token handle for |user_id| from UserManager storage.

[Nikita (slow), 2015/03/20 18:06:49]

nit: insert empty line before comments.

[Denis Kuznetsov (DE-MUC), 2015/03/20 19:50:29]

Done.

+  void DeleteToken(const user_manager::UserID& user_id);
+  // Performs token handle check for |user_id|. Will call |callback| with
+  // corresponding result.
+  void CheckToken(const user_manager::UserID& user_id,
+                  const TokenValidationCallback& callback);
+
+ private:
+  // Associates GaiaOAuthClient::Delegate with User ID and Token.
+  class TokenValidationDelegate : public gaia::GaiaOAuthClient::Delegate {
+   public:
+    TokenValidationDelegate(const base::WeakPtr<TokenHandlerUtil>& owner,
+                            const user_manager::UserID& user_id,
+                            const std::string& token,
+                            const TokenValidationCallback& callback);
+    ~TokenValidationDelegate() override;
+    void OnOAuthError() override;
+    void OnNetworkError(int response_code) override;
+    void OnGetTokenInfoResponse(
+        scoped_ptr<base::DictionaryValue> token_info) override;
+
+   private:
+    base::WeakPtr<TokenHandlerUtil> owner_;
+    user_manager::UserID user_id_;
+    std::string token_;
+    TokenValidationCallback callback_;
+
+    DISALLOW_COPY_AND_ASSIGN(TokenValidationDelegate);
+  };
+
+  void OnValidationComplete(const std::string& token);
+
+  // UserManager that stores corresponding user data.
+  user_manager::UserManager* user_manager_;
+
+  // Map of pending check operations.
+  base::ScopedPtrHashMap<std::string, TokenValidationDelegate>
+      validation_delegates_;
+  // Instance of GAIA Client

[Nikita (slow), 2015/03/20 18:06:49]

nit: dot at the end, insert empty line.

[Denis Kuznetsov (DE-MUC), 2015/03/20 19:50:29]

Done.

+  scoped_ptr<gaia::GaiaOAuthClient> gaia_client_;
+
+  base::WeakPtrFactory<TokenHandlerUtil> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(TokenHandlerUtil);
+};
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SIGNIN_TOKEN_HANDLER_UTIL_H_