update elements and fix some bugs

lib/src/paper-radio-button/paper-radio-button.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-behaviors/paper-checked-element-behavior.html">
 <link rel="import" href="../paper-ripple/paper-ripple.html">
 <link rel="import" href="../paper-styles/default-theme.html">
-<link rel="import" href="../paper-behaviors/paper-inky-focus-behavior.html">
-<link rel="import" href="../iron-checked-element-behavior/iron-checked-element-behavior.html">
 
 <!--
+Material design: [Radio button](https://www.google.com/design/spec/components/selection-controls.html#selection-controls-radio-button)
+
 `paper-radio-button` is a button that can be either checked or unchecked.
 User can tap the radio button to check or uncheck it.
 
 Use a `<paper-radio-group>` to group a set of radio buttons.  When radio buttons
 are inside a radio group, exactly one radio button in the group can be checked
 at any time.
 
 Example:
 
     <paper-radio-button></paper-radio-button>
     <paper-radio-button>Item label</paper-radio-button>
 
 ### Styling
 
 The following custom properties and mixins are available for styling:
 
 Custom property | Description | Default
 ----------------|-------------|----------
 `--paper-radio-button-unchecked-background-color` | Radio button background color when the input is not checked | `transparent`
 `--paper-radio-button-unchecked-color` | Radio button color when the input is not checked | `--primary-text-color`
 `--paper-radio-button-unchecked-ink-color` | Selected/focus ripple color when the input is not checked | `--primary-text-color`
 `--paper-radio-button-checked-color` | Radio button color when the input is checked | `--default-primary-color`
 `--paper-radio-button-checked-ink-color` | Selected/focus ripple color when the input is checked | `--default-primary-color`
 `--paper-radio-button-label-color` | Label color | `--primary-text-color`
+`--paper-radio-button-label-spacing` | Spacing between the label and the button | `10px`
 
 @group Paper Elements
 @element paper-radio-button
 @hero hero.svg
 @demo demo/index.html
 -->
 
 <dom-module id="paper-radio-button">
-  <template>
+  <template strip-whitespace>
     <style>
       :host {
         display: inline-block;
         white-space: nowrap;
       }
 
       :host(:focus) {
         outline: none;
       }
 
       #radioContainer {
         display: inline-block;
         position: relative;
         width: 16px;
         height: 16px;
         cursor: pointer;
         vertical-align: middle;
       }
 
-      :host #ink {
+      #ink {
         position: absolute;
         top: -16px;
         left: -16px;
         width: 48px;
         height: 48px;
         color: var(--paper-radio-button-unchecked-ink-color, --primary-text-color);
         opacity: 0.6;
         pointer-events: none;
       }
 
-      :host #ink[checked] {
+      :host-context([dir="rtl"]) #ink {
+        right: -15px;
+        left: auto;
+      }
+
+      #ink[checked] {
         color: var(--paper-radio-button-checked-ink-color, --default-primary-color);
       }
 
-      :host #offRadio {
+      #offRadio {
         position: absolute;
         box-sizing: content-box;
         top: 0px;
         left: 0px;
+        right: 0px;
         width: 12px;
         height: 12px;
         border-radius: 50%;
         border: solid 2px;
         background-color: var(--paper-radio-button-unchecked-background-color, transparent);
         border-color: var(--paper-radio-button-unchecked-color, --primary-text-color);
         transition: border-color 0.28s;
       }
 
-      :host #onRadio {
+      #onRadio {
         position: absolute;
         box-sizing: content-box;
         top: 4px;
         left: 4px;
+        right: 4px;
         width: 8px;
         height: 8px;
         border-radius: 50%;
         background-color: var(--paper-radio-button-checked-color, --default-primary-color);
         -webkit-transform: scale(0);
         transform: scale(0);
         transition: -webkit-transform ease 0.28s;
         transition: transform ease 0.28s;
       }
 
       :host([checked]) #offRadio {
         border-color: var(--paper-radio-button-checked-color, --default-primary-color);
       }
 
       :host([checked]) #onRadio {
         -webkit-transform: scale(1);
         transform: scale(1);
       }
 
       #radioLabel {
         position: relative;
         display: inline-block;
         vertical-align: middle;
-        margin-left: 10px;
+        margin-left: var(--paper-radio-button-label-spacing, 10px);
         white-space: normal;
         pointer-events: none;
         color: var(--paper-radio-button-label-color, --primary-text-color);
       }
 
+      :host-context([dir="rtl"]) #radioLabel {
+        margin-left: 0px;
+        margin-right: var(--paper-radio-button-label-spacing, 10px);
+      }
+
       #radioLabel[hidden] {
         display: none;
       }
 
       /* disabled state */
       :host([disabled]) {
         pointer-events: none;
       }
 
       :host([disabled]) #offRadio {
         border-color: var(--paper-radio-button-unchecked-color, --primary-text-color);
         opacity: 0.5;
       }
 
       :host([disabled][checked]) #onRadio {
         background-color: var(--paper-radio-button-unchecked-color, --primary-text-color);
         opacity: 0.5;
       }
 
       :host([disabled]) #radioLabel {
         /* slightly darker than the button, so that it's readable */
         opacity: 0.65;
       }
     </style>
 
     <div id="radioContainer">
       <div id="offRadio"></div>
       <div id="onRadio"></div>
-      <paper-ripple id="ink" class="circle" center checked$="[[checked]]"></paper-ripple>
     </div>
 
     <div id="radioLabel"><content></content></div>
-
   </template>
 
   <script>
     Polymer({
       is: 'paper-radio-button',
 
       behaviors: [
-        Polymer.PaperInkyFocusBehavior,
-        Polymer.IronCheckedElementBehavior
+        Polymer.PaperCheckedElementBehavior
       ],
 
       hostAttributes: {
         role: 'radio',
         'aria-checked': false,
         tabindex: 0
       },
 
       properties: {
         /**
          * Fired when the checked state changes due to user interaction.
          *
          * @event change
          */
 
         /**
          * Fired when the checked state changes.
          *
          * @event iron-change
          */
 
-         ariaActiveAttribute: {
-           value: 'aria-checked'
-         }
-      },
-
-      attached: function() {
-        this._isReady = true;
-
-        // Don't stomp over a user-set aria-label.
-        if (!this.getAttribute('aria-label')) {
-          this.updateAriaLabel();
+        ariaActiveAttribute: {
+          type: String,
+          value: 'aria-checked'
         }
       },
 
-      /**
-       * Update the checkbox aria-label. This is a temporary workaround not
-       * being able to observe changes in <content>
-       * (see: https://github.com/Polymer/polymer/issues/1773)
-       *
-       * Call this if you manually change the contents of the checkbox
-       * and want the aria-label to match the new contents.
-       */
-      updateAriaLabel: function() {
-        this.setAttribute('aria-label', Polymer.dom(this).textContent.trim());
-      },
-
-      _buttonStateChanged: function() {
-        if (this.disabled) {
-          return;
-        }
-        if (this._isReady) {
-          this.checked = this.active;
-        }
+      // create the element ripple inside the `radioContainer`
+      _createRipple: function() {
+        this._rippleContainer = this.$.radioContainer;
+        return Polymer.PaperInkyFocusBehaviorImpl._createRipple.call(this);
       }
     })
   </script>
-
 </dom-module>