[cros mp] Load profiles from /home/chronos/u-[$hash], add GetUserIdHashFromProfile()

chrome/browser/chromeos/profiles/profile_helper.h

 // Copyright (c) 2013 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_PROFILES_PROFILE_HELPER_H_
 #define CHROME_BROWSER_CHROMEOS_PROFILES_PROFILE_HELPER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/files/file_path.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 
 class Profile;
 
 namespace chromeos {
 
 class ProfileHelper : public UserManager::UserSessionStateObserver {
  public:
+  // Chrome OS profile directories have custom prefix.
+  // Profile path format: [user_data_dir]/u-[$hash]
+  // Ex.: /home/chronos/u-0123456789
+  static const char kProfileDirPrefix[];
+
   ProfileHelper();
   virtual ~ProfileHelper();
 
   // Returns Profile instance that corresponds to |user_id_hash|.
   static Profile* GetProfileByUserIdHash(const std::string& user_id_hash);
 
   // Returns OffTheRecord profile for use during signing phase.
   static Profile* GetSigninProfile();
 
+  // Returns user_id hash for |profile| instance or empty string if hash
+  // could not be extracted from |profile|.
+  static std::string GetUserIdHashFromProfile(Profile* profile);
+
   // Returns true if |profile| is the signin Profile. This can be used during
   // construction of the signin Profile to determine if that Profile is the
   // signin Profile.
   static bool IsSigninProfile(Profile* profile);
 
   // Initialize a bunch of services that are tied to a browser profile.
   // TODO(dzhioev): Investigate whether or not this method is needed.
   static void ProfileStartup(Profile* profile, bool process_startup);
 
+  // Returns active user profile dir in a format [u-$hash].
+  base::FilePath GetActiveUserProfileDir();
+
   // Should called once after UserManager instance has been created.
   void Initialize();
 
   // Returns hash for active user ID which is used to identify that user profile
   // on Chrome OS.
   std::string active_user_id_hash() { return active_user_id_hash_; }
 
  private:
+  friend class ProfileHelperTest;
+
   // UserManager::UserSessionStateObserver implementation:
   virtual void ActiveUserHashChanged(const std::string& hash) OVERRIDE;
 
   // Identifies path to active user profile on Chrome OS.
   std::string active_user_id_hash_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileHelper);
 };
 
 } // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_PROFILES_PROFILE_HELPER_H_