nativePostMessage top-level property
The iframe element represents its nested browsing context.
The src attribute gives the URL of a page that the element's nested browsing context is to contain. The attribute, if present, must be a valid non-empty URL potentially surrounded by spaces. If the itemprop attribute is specified on an iframe element, then the src attribute must also be specified.
DOM interface:
Implementation
// [Exposed=Window]
// interface HTMLIFrameElement : HTMLElement {
// [HTMLConstructor] constructor();
//
// [CEReactions] attribute USVString src;
// [CEReactions] attribute DOMString srcdoc;
// [CEReactions] attribute DOMString name;
// [SameObject, PutForwards=value] readonly attribute DOMTokenList sandbox;
// [CEReactions] attribute DOMString allow;
// [CEReactions] attribute boolean allowFullscreen;
// [CEReactions] attribute boolean allowPaymentRequest;
// [CEReactions] attribute DOMString width;
// [CEReactions] attribute DOMString height;
// [CEReactions] attribute DOMString referrerPolicy;
// readonly attribute Document? contentDocument;
// readonly attribute WindowProxy? contentWindow;
// Document? getSVGDocument();
// };
final Pointer<NativeFunction<NativeIframePostMessage>> nativePostMessage = Pointer.fromFunction(IFrameElement._postMessage);