Safely wrap window.top in frog dom.

client/dom/templates/dom/frog/impl_HTMLIFrameElement.darttemplate

Index: client/dom/templates/dom/frog/impl_HTMLIFrameElement.darttemplate
diff --git a/client/dom/templates/dom/frog/impl_HTMLIFrameElement.darttemplate b/client/dom/templates/dom/frog/impl_HTMLIFrameElement.darttemplate
index 8cbdf855618aedea1b41e6d0b3165cba0c8b34f6..204154d30fae31d09d13016b5d7e8f8b819afee4 100644
--- a/client/dom/templates/dom/frog/impl_HTMLIFrameElement.darttemplate
+++ b/client/dom/templates/dom/frog/impl_HTMLIFrameElement.darttemplate
@@ -12,57 +12,3 @@ $!MEMBERS
     return _DOMWindowCrossFrameImpl._createSafe(_contentWindow);
   }
 }
-
-// TODO(vsm): Unify with Dartium version.
-class _DOMWindowCrossFrameImpl implements DOMType, DOMWindow {
-  // Private window.
-  _DOMWindowJs _window;
-
-  // DOMType
-  var dartObjectLocalStorage;
-  String get typeName() => "DOMWindow";
-
-  // Fields.
-  // TODO(vsm): Wrap these two.
-  History get history() => _window.history;
-  Location get location() => _window.location;
-
-  bool get closed() => _window.closed;
-  int get length() => _window.length;
-  DOMWindow get opener() => _createDOMWindowCrossFrame(_window.opener);
-  DOMWindow get parent() => _createDOMWindowCrossFrame(_window.parent);
-  DOMWindow get top() => _createDOMWindowCrossFrame(_window.top);
-
-  // Methods.
-  void focus() {
-    _window.focus();
-  }
-
-  void blur() {
-    _window.blur();
-  }
-
-  void close() {
-    _window.close();
-  }
-
-  void postMessage(Dynamic message,
-                   String targetOrigin,
-                   [List messagePorts = null]) {
-    if (messagePorts == null) {
-      _window.postMessage(message, targetOrigin);
-    } else {
-      _window.postMessage(message, targetOrigin, messagePorts);
-    }
-  }
-
-  // Implementation support.
-  _DOMWindowCrossFrameImpl(this._window);
-
-  static DOMWindow _createSafe(w) {
-    // TODO(vsm): Check if it's the top-level window.  Return unwrapped.
-
-    // TODO(vsm): Cache or implement equality.
-    return new _DOMWindowCrossFrameImpl(w);
-  }
-}