cros: Implement cryptohome backend for pin.

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 <map>
 #include <memory>
 #include <string>
@@ skipping 150 matching lines @@
   friend class policy::DeviceStatusCollectorTest;
   friend class ExistingUserControllerTest;
   friend class extensions::ExtensionGarbageCollectorChromeOSUnitTest;
   friend class FakeChromeUserManager;
   friend class KioskTest;
   friend class MockUserManager;
   friend class MultiProfileUserControllerTest;
   friend class PrinterDetectorAppSearchEnabledTest;
   friend class ProfileHelperTest;
   friend class ProfileListChromeOSTest;
+  friend class QuickUnlockPrivateUnitTest;
   friend class SystemTrayDelegateChromeOSTest;
   friend class ash::test::MultiUserWindowManagerChromeOSTest;
   friend class arc::ArcActiveDirectoryEnrollmentTokenFetcherBrowserTest;
   friend class ::ArcAppTest;
   friend class ::SessionControllerClientTest;
   friend class ::test::BrowserFinderChromeOSTest;
 
   // Called when signin profile is cleared.
   void OnSigninProfileCleared();
 
@@ skipping 59 matching lines @@
   std::unique_ptr<FileFlusher> profile_flusher_;
 
   base::WeakPtrFactory<ProfileHelper> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileHelper);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_PROFILES_PROFILE_HELPER_H_