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

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

Index: chrome/browser/ui/views/extensions/extension_dialog_observer.h
diff --git a/chrome/browser/ui/views/extensions/extension_dialog_observer.h b/chrome/browser/ui/views/extensions/extension_dialog_observer.h
index aeb79807c900830b47559eb94dae8df4abc4dd15..d159bb0c3cd9d1f34286308403cdb59a792c76f7 100644
--- a/chrome/browser/ui/views/extensions/extension_dialog_observer.h
+++ b/chrome/browser/ui/views/extensions/extension_dialog_observer.h
@@ -18,6 +18,10 @@ class ExtensionDialogObserver {
   // 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. If not intentional, this would be typically happen
+  // in case the extension crashes.
+  virtual void ExtensionDialogTerminated(ExtensionDialog* popup) = 0;
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_EXTENSIONS_EXTENSION_DIALOG_OBSERVER_H_