[chromeos] Fix a use-after-free problem with LoginEventObserver

chrome/browser/automation/automation_event_observers.h

Index: chrome/browser/automation/automation_event_observers.h
diff --git a/chrome/browser/automation/automation_event_observers.h b/chrome/browser/automation/automation_event_observers.h
index 1587f69336610516346e18b6ea896ec17efb3fa3..972be850810689c22674fb50c9b4688033c03ad7 100644
--- a/chrome/browser/automation/automation_event_observers.h
+++ b/chrome/browser/automation/automation_event_observers.h
@@ -16,12 +16,6 @@
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
-#if defined(OS_CHROMEOS)
-namespace chromeos {
-class ExistingUserController;
-}
-#endif  // defined(OS_CHROMEOS)
-
 // AutomationEventObserver watches for a specific event, and pushes an
 // AutomationEvent into the AutomationEventQueue for each occurance.
 class AutomationEventObserver {
@@ -87,7 +81,6 @@ class LoginEventObserver
       public content::NotificationObserver {
  public:
   LoginEventObserver(AutomationEventQueue* event_queue,
-                     chromeos::ExistingUserController* controller,
                      AutomationProvider* automation);
   virtual ~LoginEventObserver();
 
@@ -102,7 +95,6 @@ class LoginEventObserver
                        const content::NotificationDetails& details) OVERRIDE;
 
  private:
-  chromeos::ExistingUserController* controller_;
   base::WeakPtr<AutomationProvider> automation_;
   content::NotificationRegistrar registrar_;