Import Polymer 0.8 and several key elements.

third_party/polymer/v0_8/components/paper-input/paper-input-char-counter.html

+<!--
+@license
+Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+
+<link rel="import" href="../polymer/polymer.html">
+<link rel="import" href="../paper-styles/paper-styles.html">
+
+<!--
+`<paper-input-char-counter>` is a character counter for use with `<paper-input-container>`.
+-->
+<dom-module id="paper-input-char-counter">
+
+  <style>
+
+    :host {
+      display: inline-block;
+      float: right;
+
+      mixin(--paper-input-container-add-on);
+      mixin(--paper-input-container-add-on-font);
+
+      mixin(--paper-input-char-counter);
+    }
+
+  </style>
+
+  <template>
+
+    <span>[[charCounter]]</span>
+
+  </template>
+
+</dom-module>
+
+<script>
+
+(function() {
+
+  Polymer({
+
+    is: 'paper-input-char-counter',
+
+    enableCustomStyleProperties: true,
+
+    hostAttributes: {
+      'add-on': ''
+    },
+
+    properties: {
+
+      /**
+       * The associated input element.
+       */
+      inputElement: {
+        type: Object
+      },
+
+      /**
+       * The current value of the input element.
+       */
+      value: {
+        type: String
+      },
+
+      /**
+       * The character counter string.
+       */
+      charCounter: {
+        computed: '_computeCharCounter(inputElement,value)',
+        type: String
+      }
+
+    },
+
+    attached: function() {
+      this.fire('addon-attached');
+    },
+
+    _computeCharCounter: function(inputElement,value) {
+      var str = value.length;
+      if (inputElement.hasAttribute('maxlength')) {
+        str += '/' + inputElement.maxLength;
+      }
+      return str;
+    }
+
+  });
+
+})();
+
+</script>