Tools/TestWebKitAPI/Tests/WebKitCocoa/CookieMessage.html - WebKit - Git at Google

 <script>
 document.cookie = "key=value";
 window.webkit.messageHandlers.testHandler.postMessage("COOKIE:" + document.cookie);
 </script>
	<script>
	document.cookie = "key=value";
	window.webkit.messageHandlers.testHandler.postMessage("COOKIE:" + document.cookie);
	</script>