Roll third_party/polymer.

third_party/polymer/v1_0/components-chromium/iron-a11y-announcer/iron-a11y-announcer-extracted.js

+(function() {
+      'use strict';
+
+      Polymer.IronA11yAnnouncer = Polymer({
+        is: 'iron-a11y-announcer',
+
+        properties: {
+
+          /**
+           * The value of mode is used to set the `aria-live` attribute
+           * for the element that will be announced. Valid values are: `off`,
+           * `polite` and `assertive`.
+           */
+          mode: {
+            type: String,
+            value: 'polite'
+          },
+
+          _text: {
+            type: String,
+            value: ''
+          }
+        },
+
+        created: function() {
+          if (!Polymer.IronA11yAnnouncer.instance) {
+            Polymer.IronA11yAnnouncer.instance = this;
+          }
+
+          document.body.addEventListener('iron-announce', this._onIronAnnounce.bind(this));
+        },
+
+        /**
+         * Cause a text string to be announced by screen readers.
+         *
+         * @param {string} text The text that should be announced.
+         */
+        announce: function(text) {
+          this._text = '';
+          this.async(function() {
+            this._text = text;
+          }, 100);
+        },
+
+        _onIronAnnounce: function(event) {
+          if (event.detail && event.detail.text) {
+            this.announce(event.detail.text);
+          }
+        }
+      });
+
+      Polymer.IronA11yAnnouncer.instance = null;
+
+      Polymer.IronA11yAnnouncer.requestAvailability = function() {
+        if (!Polymer.IronA11yAnnouncer.instance) {
+          Polymer.IronA11yAnnouncer.instance = document.createElement('iron-a11y-announcer');
+        }
+
+        document.body.appendChild(Polymer.IronA11yAnnouncer.instance);
+      };
+    })();