
       * The closest ancestor element that implements `IronResizableBehavior`.
       */
      _parentResizable: {
        type: Object,
        observer: '_parentResizableChanged'
      },

      /**
       * True if this element is currently notifying its descendant elements of
       * resize.
       */
      _notifyingDescendant: {
        type: Boolean,
        value: false
      }
    },

    listeners: {
      'iron-request-resize-notifications': '_onIronRequestResizeNotifications'
    },

    creat