rniwa/no-layout.html

## no-layout.html
<!DOCTYPE html>
<html>
<body>
<script>

var NoLayout = (function () {
    var layoutGuardCount = 0;

    function wrapMethod(name, propertyName) {
        if (NoLayout.InProduction)
            return;

        var proto = window[name].prototype;
        var descriptor = Object.getOwnPropertyDescriptor(proto, propertyName);
        var originalGetter = descriptor.value;
        var NoLayoutWrapper = function () {
            if (layoutGuardCount)
                throw new Error(name + '.prototype.' + propertyName + ' should not be called');
            return originalGetter.apply(this, arguments);
        }
        descriptor.value = NoLayoutWrapper;
        Object.defineProperty(proto, propertyName, descriptor);
    }

    wrapMethod('Element', 'getClientRects');

    return function (callback) {
        layoutGuardCount++;
        callback();
        layoutGuardCount--;
    }
})();
NoLayout.InProduction = false;

NoLayout(function () {
    document.body.getClientRects();
});

</script>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<body>
	<script>

	var NoLayout = (function () {
	var layoutGuardCount = 0;

	function wrapMethod(name, propertyName) {
	if (NoLayout.InProduction)
	return;

	var proto = window[name].prototype;
	var descriptor = Object.getOwnPropertyDescriptor(proto, propertyName);
	var originalGetter = descriptor.value;
	var NoLayoutWrapper = function () {
	if (layoutGuardCount)
	throw new Error(name + '.prototype.' + propertyName + ' should not be called');
	return originalGetter.apply(this, arguments);
	}
	descriptor.value = NoLayoutWrapper;
	Object.defineProperty(proto, propertyName, descriptor);
	}

	wrapMethod('Element', 'getClientRects');

	return function (callback) {
	layoutGuardCount++;
	callback();
	layoutGuardCount--;
	}
	})();
	NoLayout.InProduction = false;

	NoLayout(function () {
	document.body.getClientRects();
	});

	</script>
	</body>
	</html>