test(ngOptions): ensure options aren't repainted when initialize ngOptions

Since 97b3e00, ngOptions are repainting the options twice when it initializes. This test verifies that the options arent unnecessarily repainted.

Ref #15812

Author: pbr1111

test/ng/directive/ngOptionsSpec.js

@@ -779,6 +779,23 @@ describe('ngOptions', function() {
     expect(options[2]).not.toBeMarkedAsSelected();
   });
 
+
+  it('should render the options only one time', function() {
+    scope.values = ['black', 'white', 'red'];
+    createSelect({
+      'ng-model': 'value'
+    });
+
+    element.attr('ng-options', 'value for value in values');
+    var repaint = 0;
+    element[0].addEventListener('DOMSubtreeModified', function(ev) {
+      repaint++;
+      expect(repaint).toBeLessThan(2);
+    });
+
+    $compile(element)(scope);
+  });
+
   describe('disableWhen expression', function() {
 
     describe('on single select', function() {