feat(NgModel): port the URL input type to use the validators pipeline

Author: matsko

src/ng/directive/input.js

@@ -1127,12 +1127,10 @@ function numberInputType(scope, element, attr, ctrl, $sniffer, $browser) {
 function urlInputType(scope, element, attr, ctrl, $sniffer, $browser) {
   textInputType(scope, element, attr, ctrl, $sniffer, $browser);
 
-  var urlValidator = function(value) {
-    return validate(ctrl, 'url', ctrl.$isEmpty(value) || URL_REGEXP.test(value), value);
+  ctrl.$validators.url = function(modelValue, viewValue) {
+    var value = modelValue || viewValue;
+    return ctrl.$isEmpty(value) || URL_REGEXP.test(value);
   };
-
-  ctrl.$formatters.push(urlValidator);
-  ctrl.$parsers.push(urlValidator);
 }
 
 function emailInputType(scope, element, attr, ctrl, $sniffer, $browser) {