Handle termination/crashes of an extension hosted in the ExtensionDialog.

chrome/browser/ui/views/extensions/extension_dialog_observer.h

 // Copyright (c) 2011 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_VIEWS_EXTENSIONS_EXTENSION_DIALOG_OBSERVER_H_
 #define CHROME_BROWSER_UI_VIEWS_EXTENSIONS_EXTENSION_DIALOG_OBSERVER_H_
 #pragma once
 
 class ExtensionDialog;
 
 // Observer to ExtensionDialog events.
 class ExtensionDialogObserver {
  public:
   ExtensionDialogObserver();
   virtual ~ExtensionDialogObserver();
 
   // Called when the ExtensionDialog is closing. Note that it
   // is ref-counted, and thus will be released shortly after
   // making this delegate call.
   virtual void ExtensionDialogClosing(ExtensionDialog* popup) = 0;
+  // Called in case the extension hosted by the extension dialog is
+  // terminated, e.g. if the extension crashes.
+  virtual void ExtensionTerminated(ExtensionDialog* popup) = 0;
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_EXTENSIONS_EXTENSION_DIALOG_OBSERVER_H_