Add policy for limiting the session length

chrome/browser/chromeos/login/user_manager_impl.h

Index: chrome/browser/chromeos/login/user_manager_impl.h
diff --git a/chrome/browser/chromeos/login/user_manager_impl.h b/chrome/browser/chromeos/login/user_manager_impl.h
index 292d41fa5ff9b96b6ce35a22cfff5a9322a4e850..10df8b977d83497e6b5f3327731c64f11c121a48 100644
--- a/chrome/browser/chromeos/login/user_manager_impl.h
+++ b/chrome/browser/chromeos/login/user_manager_impl.h
@@ -30,6 +30,7 @@ class ProfileSyncService;
 namespace chromeos {
 
 class RemoveUserDelegate;
+class SessionLengthLimiter;
 
 // Implementation of the UserManager.
 class UserManagerImpl : public UserManager,
@@ -81,6 +82,7 @@ class UserManagerImpl : public UserManager,
   virtual bool IsLoggedInAsGuest() const OVERRIDE;
   virtual bool IsLoggedInAsStub() const OVERRIDE;
   virtual bool IsSessionStarted() const OVERRIDE;
+  virtual bool HasBrowserRestarted() const OVERRIDE;
   virtual bool IsUserNonCryptohomeDataEphemeral(
       const std::string& email) const OVERRIDE;
   virtual void AddObserver(UserManager::Observer* obs) OVERRIDE;
@@ -209,6 +211,9 @@ class UserManagerImpl : public UserManager,
   // User avatar manager.
   scoped_ptr<UserImageManagerImpl> user_image_manager_;
 
+  // Session length limiter.
+  scoped_ptr<SessionLengthLimiter> session_length_limiter_;
+
   DISALLOW_COPY_AND_ASSIGN(UserManagerImpl);
 };