function strings for declarative event handlers appear in the markup #378

<polymer-element name="x-foo">
  <template>
    <div on-tap="{{tapHandler}}">tap me!</div>
  </template>
  <script>
    Polymer('x-foo', {
      tapHandler: function() {
        console.log('tapped!')
      }
    });
  </script>
</polymer-element>

<x-foo></x-foo>

<div on-tap="function () {
        console.log('tapped!')
      }">tap me!</div>