Revert of Revert of Remove prefixed Pointer Lock API.

LayoutTests/http/tests/resources/pointer-lock/pointer-lock-test-harness-prefixed.js

-// Automatically add doNextStepButton to document for manual tests.
-if (!window.testRunner) {
-    setTimeout(function () {
-        if (window.doNextStepButtonDisabled)
-            return;
-        doNextStepButton = document.body.insertBefore(document.createElement("button"), document.body.firstChild);
-        doNextStepButton.onclick = doNextStep;
-        doNextStepButton.innerText = "doNextStep button for manual testing. Use keyboard to select button and press (TAB, then SPACE).";
-    }, 0);
-}
-
-function runOnKeyPress(fn)
-{
-    function keypressHandler() {
-        document.removeEventListener('keypress', keypressHandler, false);
-        fn();
-    }
-    document.addEventListener('keypress', keypressHandler, false);
-
-    if (window.testRunner)
-        eventSender.keyDown(" ", []);
-}
-
-function doNextStep(args)
-{
-    args = args || {};
-    if (!window.testRunner && args.withUserGesture)
-      return; // Wait for human to press doNextStep button.
-
-    if (typeof(currentStep) == "undefined")
-        currentStep = 0;
-
-    setTimeout(function () {
-        var thisStep = currentStep++;
-        if (thisStep < todo.length)
-            if (args.withUserGesture)
-                runOnKeyPress(todo[thisStep]);
-            else
-                todo[thisStep]();
-        else if (thisStep == todo.length)
-            setTimeout(function () { finishJSTest(); }, 0); // Deferred so that excessive doNextStep calls will be observed.
-        else
-            testFailed("doNextStep called too many times.");
-    }, 0);
-}
-
-function doNextStepWithUserGesture()
-{
-    doNextStep({withUserGesture: true});
-}
-
-function eventExpected(eventHandlerName, message, expectedCalls, targetHanderNode)
-{
-    targetHanderNode[eventHandlerName] = function () {
-        switch (expectedCalls--) {
-        case 0:
-            testFailed(eventHandlerName + " received after: " + message);
-            finishJSTest();
-            break;
-        case 1:
-            doNextStep();
-        default:
-            testPassed(eventHandlerName + " received after: " + message);
-        };
-    };
-};
-
-function expectOnlyChangeEvent(message, targetDocument) {
-    debug("     " + message);
-    targetDocument = targetDocument !== undefined ? targetDocument : document;
-    eventExpected("onwebkitpointerlockchange", message, 1, targetDocument);
-    eventExpected("onwebkitpointerlockerror", message, 0, targetDocument);
-};
-
-function expectOnlyErrorEvent(message, targetDocument) {
-    debug("     " + message);
-    targetDocument = targetDocument !== undefined ? targetDocument : document;
-    eventExpected("onwebkitpointerlockchange", message, 0, targetDocument);
-    eventExpected("onwebkitpointerlockerror", message, 1, targetDocument);
-};
-
-function expectNoEvents(message, targetDocument) {
-    debug("     " + message);
-    targetDocument = targetDocument !== undefined ? targetDocument : document;
-    eventExpected("onwebkitpointerlockchange", message, 0, targetDocument);
-    eventExpected("onwebkitpointerlockerror", message, 0, targetDocument);
-};
-