Upgrade to 1.0 and switch clients to dom-repeat where needed.

third_party/polymer/v0_8/components/iron-a11y-announcer/README.md

+iron-a11y-announcer
+===================
+
+`iron-a11y-announcer` is a singleton element that is intended to add a11y
+to features that require on-demand announcement from screen readers. In
+order to make use of the announcer, it is best to request its availability
+in the announcing element.
+
+Example:
+
+    Polymer({
+      is: 'x-chatty',
+      attached: function() {
+        // This will create the singlton element if it has not
+        // been created yet:
+        Polymer.IronA11yAnnouncer.requestAvailability();
+      }
+    });
+    
+After the `iron-a11y-announcer` has been made available, elements can
+make announces by firing bubbling `iron-announce` events.
+
+Example:
+
+    this.fire('iron-announce', {
+      text: 'This is an announcement!'
+    }, { bubbles: true });
+    
+Note: announcements are only audible if you have a screen reader enabled.