Revert of Start session fail causes restart chrome

chromeos/dbus/session_manager_client.h

Index: chromeos/dbus/session_manager_client.h
diff --git a/chromeos/dbus/session_manager_client.h b/chromeos/dbus/session_manager_client.h
index 9e3ca89d2a103393003d2205004e0cd83ec9c3bf..925ce5cfa171faf119fd6b13104655997d8ed650 100644
--- a/chromeos/dbus/session_manager_client.h
+++ b/chromeos/dbus/session_manager_client.h
@@ -70,13 +70,8 @@
   // Restarts a job referenced by |pid| with the provided command line.
   virtual void RestartJob(int pid, const std::string& command_line) = 0;
 
-  // Used for StartSession. Takes a boolean indicating whether the
-  // operation was successful or not.
-  typedef base::Callback<void(bool success)> StartSessionCallback;
-
   // Starts the session for the user.
-  virtual void StartSession(const std::string& user_email,
-                            const StartSessionCallback& callback) = 0;
+  virtual void StartSession(const std::string& user_email) = 0;
 
   // Stops the current session.
   virtual void StopSession() = 0;