Replacing WebUIBindings use of CPPBoundClass with v8::Extension.

chrome/browser/resources/tab_modal_confirm_dialog.html

Index: chrome/browser/resources/tab_modal_confirm_dialog.html
diff --git a/chrome/browser/resources/tab_modal_confirm_dialog.html b/chrome/browser/resources/tab_modal_confirm_dialog.html
index 8637543beaff7e976460777ded1ed1569dd4a6f0..97fe0975a856e1a530c87f80bca982ea1d9bab2f 100644
--- a/chrome/browser/resources/tab_modal_confirm_dialog.html
+++ b/chrome/browser/resources/tab_modal_confirm_dialog.html
@@ -52,7 +52,8 @@
     }
 
     function load() {
-      i18nTemplate.process(document, JSON.parse(chrome.dialogArguments));
+      i18nTemplate.process(document, JSON.parse(
+          chrome.getVariableValue('dialogArguments')));
       document.addEventListener('keydown', handleKeyDown);
       $('form').onsubmit = handleSubmit;
       $('cancel').onclick = cancel;