Properly handle failure modes in the wildcard login check.

chrome/browser/chromeos/policy/wildcard_login_checker.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 CHROME_BROWSER_CHROMEOS_POLICY_WILDCARD_LOGIN_CHECKER_H_
 #define CHROME_BROWSER_CHROMEOS_POLICY_WILDCARD_LOGIN_CHECKER_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "components/policy/core/common/cloud/user_info_fetcher.h"
 #include "google_apis/gaia/google_service_auth_error.h"
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace policy {
 
 class PolicyOAuth2TokenFetcher;
 
 // Performs online verification whether wildcard login is allowed, i.e. whether
 // the user is a hosted user. This class performs an asynchronous check and
 // reports the result via a callback.
 class WildcardLoginChecker : public UserInfoFetcher::Delegate {
  public:
-  typedef base::Callback<void(bool)> StatusCallback;
+  // Indicates result of the wildcard login check.
+  enum Result {
+    RESULT_ALLOWED,  // Wildcard check succeeded, login allowed.
+    RESULT_BLOCKED,  // Check completed, but user should be blocked.
+    RESULT_FAILED,   // Failure due to network errors etc.
+  };
+
+  typedef base::Callback<void(Result)> StatusCallback;
 
   WildcardLoginChecker();
   virtual ~WildcardLoginChecker();
 
   // Starts checking. The result will be reported via |callback_|.
   void Start(scoped_refptr<net::URLRequestContextGetter> signin_context,
              const StatusCallback& callback);
 
   // Starts checking with a provided access token.
   void StartWithAccessToken(const std::string& access_token,
                             const StatusCallback& callback);
 
   // UserInfoFetcher::Delegate:
   virtual void OnGetUserInfoSuccess(const base::DictionaryValue* response)
       OVERRIDE;
   virtual void OnGetUserInfoFailure(const GoogleServiceAuthError& error)
       OVERRIDE;
 
  private:
   // Starts the check after successful token minting.
   void OnPolicyTokenFetched(const std::string& access_token,
                             const GoogleServiceAuthError& error);
 
   // Starts the user info fetcher.
   void StartUserInfoFetcher(const std::string& access_token);
 
   // Handles the response of the check and calls ReportResult().
-  void OnCheckCompleted(bool result);
+  void OnCheckCompleted(Result result);
 
   StatusCallback callback_;
 
   scoped_ptr<PolicyOAuth2TokenFetcher> token_fetcher_;
   scoped_ptr<UserInfoFetcher> user_info_fetcher_;
 
   base::Time start_timestamp_;
   base::Time token_available_timestamp_;
 
   DISALLOW_COPY_AND_ASSIGN(WildcardLoginChecker);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_CHROMEOS_POLICY_WILDCARD_LOGIN_CHECKER_H_