Implement ephemeral users

chrome/browser/chromeos/login/user_manager.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 CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 40 matching lines @@
   static UserManager* Get();
 
   // Set UserManager singleton object for test purpose only!
   static void Set(UserManager* mock);
 
   // Registers user manager preferences.
   static void RegisterPrefs(PrefService* local_state);
 
   virtual ~UserManager();
 
-  // Returns a list of the users who have logged into this device previously.
-  // It is sorted in order of recency, with most recent at the beginning.
+  // Returns a list of users who have logged into this device previously. This
+  // is sorted by last login date with the most recent user at the beginning.
   virtual const UserList& GetUsers() const = 0;
 
-  // Indicates that a user with the given email has just logged in.
-  // The persistent list will be updated accordingly.
+  // Indicates that a user with the given email has just logged in. The
+  // persistent list is updated accordingly if the user is not ephemeral.
   virtual void UserLoggedIn(const std::string& email) = 0;
 
   // Indicates that user just logged on as the demo user.
   virtual void DemoUserLoggedIn() = 0;
 
   // Indicates that user just started incognito session.
   virtual void GuestUserLoggedIn() = 0;
 
   // Removes the user from the device. Note, it will verify that the given user
   // isn't the owner, so calling this method for the owner will take no effect.
   // Note, |delegate| can be NULL.
   virtual void RemoveUser(const std::string& email,
                           RemoveUserDelegate* delegate) = 0;
 
   // Removes the user from the persistent list only. Also removes the user's
   // picture.
   virtual void RemoveUserFromList(const std::string& email) = 0;
 
-  // Returns true if given user has logged into the device before.
+  // Returns true if a user with the given email address is found in the
+  // persistent list or currently logged in as ephemeral.
   virtual bool IsKnownUser(const std::string& email) const = 0;
 
-  // Returns a user with given email or |NULL| if no such user exists.
+  // Returns the user with the given email address if found in the persistent
+  // list or currently logged in as ephemeral. Returns |NULL| otherwise.
   virtual const User* FindUser(const std::string& email) const = 0;
 
   // Returns the logged-in user.
   virtual const User& GetLoggedInUser() const = 0;
   virtual User& GetLoggedInUser() = 0;
 
   // Returns true if given display name is unique.
   virtual bool IsDisplayNameUnique(const std::string& display_name) const = 0;
 
   // Saves user's oauth token status in local state preferences.
@@ skipping 40 matching lines @@
   // |reason| is an arbitraty string (used to report UMA histograms with
   // download times).
   virtual void DownloadProfileImage(const std::string& reason) = 0;
 
   // Returns true if current user is an owner.
   virtual bool IsCurrentUserOwner() const = 0;
 
   // Returns true if current user is not existing one (hasn't signed in before).
   virtual bool IsCurrentUserNew() const = 0;
 
+  // Returns true if the current user is ephemeral.
+  virtual bool IsCurrentUserEphemeral() const = 0;
+
   // Returns true if user is signed in.
   virtual bool IsUserLoggedIn() const = 0;
 
   // Returns true if we're logged in as a demo user.
   virtual bool IsLoggedInAsDemoUser() const = 0;
 
   // Returns true if we're logged in as a Guest.
   virtual bool IsLoggedInAsGuest() const = 0;
 
   virtual void AddObserver(Observer* obs) = 0;
   virtual void RemoveObserver(Observer* obs) = 0;
 
   virtual void NotifyLocalStateChanged() = 0;
 
   // Returns the result of the last successful profile image download, if any.
   // Otherwise, returns an empty bitmap.
   virtual const SkBitmap& DownloadedProfileImage() const = 0;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_USER_MANAGER_H_