Remove prefixed Pointer Lock API.

LayoutTests/http/tests/resources/pointer-lock/iframe-common-prefixed.js

-function thisFileName()
-{
-    return window.location.href.split("/").pop();
-}
-
-window.onmessage = function (messageEvent) {
-    switch (messageEvent.data[0]) {
-    case "eval":
-        eval(messageEvent.data[1]);
-        break;
-    case "pass message down":
-        iframe = document.getElementsByTagName("iframe")[0];
-        iframe.contentWindow.postMessage(messageEvent.data.slice(1), "*");
-        break;
-    default:
-        // Pass all other messages up to parent.
-        parent.postMessage(messageEvent.data, "*");
-    }
-}
-
-document.onwebkitpointerlockchange = function () {
-    parent.postMessage(thisFileName() + " onwebkitpointerlockchange, document.webkitPointerLockElement = " + document.webkitPointerLockElement, "*");
-}
-
-document.onwebkitpointerlockerror = function () {
-    parent.postMessage(thisFileName() + " onwebkitpointerlockerror", "*");
-}