refactor(ngModel): use minErr directly for correct doc creation

The minerr_errors extractor of the closure compiler cannot detect minErrs that are not
thrown in the form of 'throw minErr(...'

Closes angular#12386

Author: Narretz

src/ng/directive/input.js

@@ -6,7 +6,6 @@
   DIRTY_CLASS: false,
   UNTOUCHED_CLASS: false,
   TOUCHED_CLASS: false,
-  $ngModelMinErr: false,
 */
 
 // Regex code is obtained from SO: https://stackoverflow.com/questions/3143070/javascript-regex-iso-datetime#answer-3143231
@@ -1239,7 +1238,7 @@ function createDateInputType(type, regexp, parseDate, format) {
 
     ctrl.$formatters.push(function(value) {
       if (value && !isDate(value)) {
-        throw $ngModelMinErr('datefmt', 'Expected `{0}` to be a date', value);
+        throw minErr('ngModel')('datefmt', 'Expected `{0}` to be a date', value);
       }
       if (isValidDate(value)) {
         previousDate = value;
@@ -1315,7 +1314,7 @@ function numberInputType(scope, element, attr, ctrl, $sniffer, $browser) {
   ctrl.$formatters.push(function(value) {
     if (!ctrl.$isEmpty(value)) {
       if (!isNumber(value)) {
-        throw $ngModelMinErr('numfmt', 'Expected `{0}` to be a number', value);
+        throw minErr('ngModel')('numfmt', 'Expected `{0}` to be a number', value);
       }
       value = value.toString();
     }

src/ng/directive/ngModel.js

@@ -16,9 +16,6 @@ var VALID_CLASS = 'ng-valid',
     TOUCHED_CLASS = 'ng-touched',
     PENDING_CLASS = 'ng-pending';
 
-
-var $ngModelMinErr = new minErr('ngModel');
-
 /**
  * @ngdoc type
  * @name ngModel.NgModelController
@@ -268,7 +265,7 @@ var NgModelController = ['$scope', '$exceptionHandler', '$attrs', '$element', '$
         }
       };
     } else if (!parsedNgModel.assign) {
-      throw $ngModelMinErr('nonassign', "Expression '{0}' is non-assignable. Element: {1}",
+      throw minErr('ngModel')('nonassign', "Expression '{0}' is non-assignable. Element: {1}",
           $attr.ngModel, startingTag($element));
     }
   };
@@ -599,7 +596,7 @@ var NgModelController = ['$scope', '$exceptionHandler', '$attrs', '$element', '$
       forEach(ctrl.$asyncValidators, function(validator, name) {
         var promise = validator(modelValue, viewValue);
         if (!isPromiseLike(promise)) {
-          throw $ngModelMinErr("$asyncValidators",
+          throw minErr('ngModel')("$asyncValidators",
             "Expected asynchronous validator to return a promise but got '{0}' instead.", promise);
         }
         setValidity(name, undefined);