AX: Calendar Picker: Initial day selection should notify ActiveDescendantChanged a11y event.

AXRenderObject assumes that both of the ancestor element and the active
descendant element have their renderers.

BUG=123896

Review URL: https://codereview.chromium.org/550853002

git-svn-id: svn://svn.chromium.org/blink/trunk@181547 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/fast/forms/calendar-picker/date-picker-ax-expected.txt

@@ -4,6 +4,8 @@ On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE
 
 
 Focused: AXDescription: 
+Focused: AXDescription: Sunday, January 2, 2000
+PASS Received ActiveDescendantChanged
 Focused: AXDescription: Monday, January 3, 2000
 PASS Received ActiveDescendantChanged
 PASS successfullyParsed is true

third_party/WebKit/LayoutTests/fast/forms/calendar-picker/date-picker-ax.html

@@ -16,9 +16,11 @@ window.accessibilityController.setNotificationListener(function(axnode, type) {
         debug('Focused: ' + accessibilityController.focusedElement.description);
     } else if (type == 'ActiveDescendantChanged') {
         testPassed('Received ActiveDescendantChanged');
-        finishJSTest();
+        if (++activeDescendantCounter >= 2)
+            finishJSTest();
     }
 });
+var activeDescendantCounter = 0;
 var date1 = document.getElementById('date1');
 openPicker(date1, test1);
 

third_party/WebKit/Source/web/resources/calendarPicker.js

@@ -3519,6 +3519,7 @@ CalendarTableView.prototype.updateCells = function() {
     var currentMonth = this.calendarPicker.currentMonth();
     var firstDayInCurrentMonth = currentMonth.firstDay().valueOf();
     var lastDayInCurrentMonth = currentMonth.lastDay().valueOf();
+    var activeDayCell = null;
     for (var dayString in this._dayCells) {
         var dayCell = this._dayCells[dayString];
         var day = dayCell.day;
@@ -3527,7 +3528,7 @@ CalendarTableView.prototype.updateCells = function() {
         var isHighlighted = day >= firstDayInHighlight && day <= lastDayInHighlight;
         dayCell.setHighlighted(isHighlighted);
         if (isHighlighted && firstDayInHighlight == lastDayInHighlight)
-            this.element.setAttribute("aria-activedescendant", dayCell.element.id);
+            activeDayCell = dayCell;
         dayCell.setIsInCurrentMonth(day >= firstDayInCurrentMonth && day <= lastDayInCurrentMonth);
         dayCell.setDisabled(!this.calendarPicker.isValidDay(day));
     }
@@ -3540,6 +3541,13 @@ CalendarTableView.prototype.updateCells = function() {
             weekNumberCell.setDisabled(!this.calendarPicker.isValid(week));
         }
     }
+    if (activeDayCell) {
+        // Ensure a renderer because an element with no renderer doesn't post
+        // activedescendant events. This shouldn't run in the above |for| loop
+        // to avoid CSS transition.
+        activeDayCell.element.offsetLeft;
+        this.element.setAttribute("aria-activedescendant", activeDayCell.element.id);
+    }
 };
 
 /**