Remove implicit update when adding a listener in passwords private API.

chrome/browser/extensions/api/passwords_private/passwords_private_event_router.h

Index: chrome/browser/extensions/api/passwords_private/passwords_private_event_router.h
diff --git a/chrome/browser/extensions/api/passwords_private/passwords_private_event_router.h b/chrome/browser/extensions/api/passwords_private/passwords_private_event_router.h
index c7a7f51f32ae10455909a5ecad8fe879b48f5dd9..cea416f75549491bbe144f2cff269494b6995876 100644
--- a/chrome/browser/extensions/api/passwords_private/passwords_private_event_router.h
+++ b/chrome/browser/extensions/api/passwords_private/passwords_private_event_router.h
@@ -19,9 +19,7 @@ namespace extensions {
 // An event router that observes changes to saved passwords and password
 // exceptions and notifies listeners to the onSavedPasswordsListChanged and
 // onPasswordExceptionsListChanged events of changes.
-class PasswordsPrivateEventRouter :
-    public KeyedService,
-    public EventRouter::Observer {
+class PasswordsPrivateEventRouter : public KeyedService {
  public:
   static PasswordsPrivateEventRouter* Create(
       content::BrowserContext* browser_context);
@@ -49,12 +47,6 @@ class PasswordsPrivateEventRouter :
  protected:
   explicit PasswordsPrivateEventRouter(content::BrowserContext* context);
 
-  // KeyedService overrides:
-  void Shutdown() override;
-
-  // EventRouter::Observer overrides:
-  void OnListenerAdded(const EventListenerInfo& details) override;
-
  private:
   void SendSavedPasswordListToListeners();
   void SendPasswordExceptionListToListeners();