AX: Calendar Picker: Apply aria-activedescendant to YearListView.

Source/web/resources/calendarPicker.js

 "use strict";
 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 1542 matching lines @@
 ScrollView.prototype.contentPositionForContentOffset = function(offset) {
     return offset - this._partitionNumber * ScrollView.PartitionHeight;
 };
 
 /**
  * @constructor
  * @extends View
  */
 function ListCell() {
     View.call(this, createElement("div", ListCell.ClassNameListCell));
-    this.element.setAttribute("role", "gridcell");
     
     /**
      * @type {!number}
      */
     this.row = NaN;
     /**
      * @type {!number}
      */
     this._width = 0;
     /**
@@ skipping 563 matching lines @@
     this.label.style.lineHeight = (YearListCell.Height - YearListCell.BorderBottomWidth) + "px";
 
     /**
      * @type {!Array} Array of the 12 month button elements.
      * @const
      */
     this.monthButtons = [];
     var monthChooserElement = createElement("div", YearListCell.ClassNameMonthChooser);
     for (var r = 0; r < YearListCell.ButtonRows; ++r) {
         var buttonsRow = createElement("div", YearListCell.ClassNameMonthButtonsRow);
+        buttonsRow.setAttribute("role", "row");
         for (var c = 0; c < YearListCell.ButtonColumns; ++c) {
             var month = c + r * YearListCell.ButtonColumns;
             var button = createElement("div", YearListCell.ClassNameMonthButton, shortMonthLabels[month]);
+            button.setAttribute("role", "gridcell");
             button.dataset.month = month;
             buttonsRow.appendChild(button);
             this.monthButtons.push(button);
         }
         monthChooserElement.appendChild(buttonsRow);
     }
     this.element.appendChild(monthChooserElement);
 
     /**
      * @type {!boolean}
@@ skipping 308 matching lines @@
 
 /**
  * @param {!number} row
  * @return {!YearListCell}
  * @override
  */
 YearListView.prototype.prepareNewCell = function(row) {
     var cell = YearListCell._recycleBin.pop() || new YearListCell(global.params.shortMonthLabels);
     cell.reset(row);
     cell.setSelected(this.selectedRow === row);
-    if (this.highlightedMonth && row === this.highlightedMonth.year - 1) {
-        cell.monthButtons[this.highlightedMonth.month].classList.add(YearListCell.ClassNameHighlighted);
-    }
     for (var i = 0; i < cell.monthButtons.length; ++i) {
         var month = new Month(row + 1, i);
+        cell.monthButtons[i].id = month.toString();
         cell.monthButtons[i].setAttribute("aria-disabled", this._minimumMonth > month || this._maximumMonth < month ? "true" : "false");
+        cell.monthButtons[i].setAttribute("aria-label", month.toLocaleString());
+    }
+    if (this.highlightedMonth && row === this.highlightedMonth.year - 1) {
+        var monthButton = cell.monthButtons[this.highlightedMonth.month];
+        monthButton.classList.add(YearListCell.ClassNameHighlighted);
+        // aira-activedescendant assumes both elements have renderers, and
+        // |monthButton| might have no renderer yet.
+        var element = this.element;
+        setTimeout(function() {
+            element.setAttribute("aria-activedescendant", monthButton.id);
+        }, 0);
     }
     var animator = this._runningAnimators[row];
     if (animator)
         cell.setHeight(animator.currentValue);
     else if (row === this.selectedRow)
         cell.setHeight(YearListCell.SelectedHeight);
     else
         cell.setHeight(YearListCell.Height);
     return cell;
 };
@@ skipping 105 matching lines @@
 };
 
 YearListView.prototype.dehighlightMonth = function() {
     if (!this.highlightedMonth)
         return;
     var monthButton = this.buttonForMonth(this.highlightedMonth);
     if (monthButton) {
         monthButton.classList.remove(YearListCell.ClassNameHighlighted);
     }
     this.highlightedMonth = null;
+    this.element.removeAttribute("aria-activedescendant");
 };
 
 /**
  * @param {!Month} month
  */
 YearListView.prototype.highlightMonth = function(month) {
     if (this.highlightedMonth && this.highlightedMonth.equals(month))
         return;
     this.dehighlightMonth();
     this.highlightedMonth = month;
     if (!this.highlightedMonth)
         return;
     var monthButton = this.buttonForMonth(this.highlightedMonth);
     if (monthButton) {
         monthButton.classList.add(YearListCell.ClassNameHighlighted);
+        this.element.setAttribute("aria-activedescendant", monthButton.id);
     }
 };
 
 /**
  * @param {!Month} month
  */
 YearListView.prototype.show = function(month) {
     this._ignoreMouseOutUntillNextMouseOver = true;
     
     this.scrollToRow(month.year - 1, false);
@@ skipping 391 matching lines @@
 /**
  * @constructor
  * @extends ListCell
  */
 function DayCell() {
     ListCell.call(this);
     this.element.classList.add(DayCell.ClassNameDayCell);
     this.element.style.width = DayCell.Width + "px";
     this.element.style.height = DayCell.Height + "px";
     this.element.style.lineHeight = (DayCell.Height - DayCell.PaddingSize * 2) + "px";
+    this.element.setAttribute("role", "gridcell");
     /**
      * @type {?Day}
      */
     this.day = null;
 };
 
 DayCell.prototype = Object.create(ListCell.prototype);
 
 DayCell.Width = 34;
 DayCell.Height = hasInaccuratePointingDevice() ? 34 : 20;
@@ skipping 1021 matching lines @@
         event.stopPropagation();
         event.preventDefault();
     }
 };
 
 if (window.dialogArguments) {
     initialize(dialogArguments);
 } else {
     window.addEventListener("message", handleMessage, false);
 }