fix(datepicker): remove invalid aria-expanded (#11740)

use ARIA 1.1 value for `aria-has-popup`

Relates to #11475

Author: Splaktar

src/components/datepicker/js/datepickerDirective.js

@@ -109,8 +109,7 @@
           '<input ' +
             (ariaLabelValue ? 'aria-label="' + ariaLabelValue + '" ' : '') +
             'class="md-datepicker-input" ' +
-            'aria-haspopup="true" ' +
-            'aria-expanded="{{ctrl.isCalendarOpen}}" ' +
+            'aria-haspopup="dialog" ' +
             'ng-focus="ctrl.setFocused(true)" ' +
             'ng-blur="ctrl.setFocused(false)"> ' +
             triangleButton +
@@ -325,7 +324,7 @@
     this.isFocused = false;
 
     /** @type {boolean} */
-    this.isDisabled;
+    this.isDisabled = undefined;
     this.setDisabled($element[0].disabled || angular.isString($attrs.disabled));
 
     /** @type {boolean} Whether the date-picker's calendar pane is open. */
@@ -334,7 +333,7 @@
     /** @type {boolean} Whether the calendar should open when the input is focused. */
     this.openOnFocus = $attrs.hasOwnProperty('mdOpenOnFocus');
 
-    /** @final */
+    /** @type {Object} Instance of the mdInputContainer controller */
     this.mdInputContainer = null;
 
     /**
@@ -648,9 +647,9 @@
   };
 
   /**
-   * Check to see if the input is valid as the validation should fail if the model is invalid
+   * Check to see if the input is valid, as the validation should fail if the model is invalid.
    *
-   * @param {String} inputString
+   * @param {string} inputString
    * @param {Date} parsedDate
    * @return {boolean} Whether the input is valid
    */

src/components/datepicker/js/datepickerDirective.spec.js

@@ -851,22 +851,6 @@ describe('md-datepicker', function() {
       expect(controller.calendarPane.id).toBe(ariaAttr);
     });
 
-    it('should toggle the aria-expanded value', function() {
-      expect(controller.ngInputElement.attr('aria-expanded')).toBe('false');
-
-      controller.openCalendarPane({
-        target: controller.inputElement
-      });
-      scope.$apply();
-
-      expect(controller.ngInputElement.attr('aria-expanded')).toBe('true');
-
-      controller.closeCalendarPane();
-      scope.$apply();
-
-      expect(controller.ngInputElement.attr('aria-expanded')).toBe('false');
-    });
-
     describe('tabindex behavior', function() {
       beforeEach(function() {
         ngElement && ngElement.remove();