Use WeakPtr to simplify AutofillPopupControllerImpl memory management

chrome/browser/ui/autofill/autofill_popup_delegate.h

 // Copyright (c) 2012 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_UI_AUTOFILL_AUTOFILL_POPUP_DELEGATE_H_
 #define CHROME_BROWSER_UI_AUTOFILL_AUTOFILL_POPUP_DELEGATE_H_
 
 #include "base/string16.h"
 
+namespace content {
+class KeyboardListener;
+}
+
 // An interface for interaction with AutofillPopupController. Will be notified
 // of events by the controller.
 class AutofillPopupDelegate {
  public:
-  virtual ~AutofillPopupDelegate() { }
+  // Called when the Autofill popup is shown. |listener| may be used to pass
+  // keyboard events to the popup.
+  virtual void OnPopupShown(content::KeyboardListener* listener) = 0;
+
+  // Called when the Autofill popup is hidden. |listener| must be unregistered
+  // if it was registered in OnPopupShown.
+  virtual void OnPopupHidden(content::KeyboardListener* listener) = 0;
 
   // Called when the autofill suggestion indicated by |identifier| has been
   // temporarily selected (e.g., hovered).
   virtual void DidSelectSuggestion(int identifier) = 0;
 
   // Inform the delegate that a row in the popup has been chosen.
   virtual void DidAcceptSuggestion(const string16& value, int identifier) = 0;
 
   // Delete the described suggestion.
   virtual void RemoveSuggestion(const string16& value, int identifier) = 0;
 
   // Informs the delegate that the Autofill previewed form should be cleared.
   virtual void ClearPreviewedForm() = 0;
-
-  // Called to inform the delegate the controller is experiencing destruction.
-  virtual void ControllerDestroyed() = 0;
 };
 
 #endif  // CHROME_BROWSER_UI_AUTOFILL_AUTOFILL_POPUP_DELEGATE_H_