[third_party] add polymer 1.2.3

polymer_1.2.3/bower_components/iron-form-element-behavior/iron-form-element-behavior.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">
+
+<script>
+  /**
+  Polymer.IronFormElementBehavior enables a custom element to be included
+  in an `iron-form`.
+
+  @demo demo/index.html
+  @polymerBehavior
+  */
+  Polymer.IronFormElementBehavior = {
+
+    properties: {
+      /**
+       * Fired when the element is added to an `iron-form`.
+       *
+       * @event iron-form-element-register
+       */
+
+      /**
+       * Fired when the element is removed from an `iron-form`.
+       *
+       * @event iron-form-element-unregister
+       */
+
+      /**
+       * The name of this element.
+       */
+      name: {
+        type: String
+      },
+
+      /**
+       * The value for this element.
+       */
+      value: {
+        notify: true,
+        type: String
+      },
+
+      /**
+       * Set to true to mark the input as required. If used in a form, a
+       * custom element that uses this behavior should also use
+       * Polymer.IronValidatableBehavior and define a custom validation method.
+       * Otherwise, a `required` element will always be considered valid.
+       * It's also strongly recommended to provide a visual style for the element
+       * when its value is invalid.
+       */
+      required: {
+        type: Boolean,
+        value: false
+      },
+
+      /**
+       * The form that the element is registered to.
+       */
+      _parentForm: {
+        type: Object
+      }
+    },
+
+    attached: function() {
+      // Note: the iron-form that this element belongs to will set this
+      // element's _parentForm property when handling this event.
+      this.fire('iron-form-element-register');
+    },
+
+    detached: function() {
+      if (this._parentForm) {
+        this._parentForm.fire('iron-form-element-unregister', {target: this});
+      }
+    }
+
+  };
+
+</script>