update elements and fix some bugs

lib/paper_button.dart

 // DO NOT EDIT: auto-generated with `pub run custom_element_apigen:update`
 
 /// Dart API for the polymer element `paper_button`.
 @HtmlImport('paper_button_nodart.html')
 library polymer_elements.lib.src.paper_button.paper_button;
 
 import 'dart:html';
 import 'dart:js' show JsArray, JsObject;
 import 'package:web_components/web_components.dart';
 import 'package:polymer_interop/polymer_interop.dart';
 import 'paper_button_behavior.dart';
 import 'iron_button_state.dart';
 import 'iron_a11y_keys_behavior.dart';
 import 'iron_control_state.dart';
+import 'paper_ripple_behavior.dart';
 import 'paper_material.dart';
 import 'paper_ripple.dart';
 import 'iron_flex_layout.dart';
 
-/// Material Design: <a href="http://www.google.com/design/spec/components/buttons.html">Buttons</a>
+/// Material design: [Buttons](https://www.google.com/design/spec/components/buttons.html)
 ///
 /// `paper-button` is a button. When the user touches the button, a ripple effect emanates
 /// from the point of contact. It may be flat or raised. A raised button is styled with a
 /// shadow.
 ///
 /// Example:
 ///
 ///     <paper-button>Flat button</paper-button>
 ///     <paper-button raised>Raised button</paper-button>
 ///     <paper-button noink>No ripple effect</paper-button>
@@ skipping 35 matching lines @@
 /// The following custom properties and mixins are also available for styling:
 ///
 /// Custom property | Description | Default
 /// ----------------|-------------|----------
 /// `--paper-button-ink-color` | Background color of the ripple | `Based on the button's color`
 /// `--paper-button` | Mixin applied to the button | `{}`
 /// `--paper-button-disabled` | Mixin applied to the disabled button. Note that you can also use the `paper-button[disabled]` selector | `{}`
 /// `--paper-button-flat-keyboard-focus` | Mixin applied to a flat button after it's been focused using the keyboard | `{}`
 /// `--paper-button-raised-keyboard-focus` | Mixin applied to a raised button after it's been focused using the keyboard | `{}`
 @CustomElementProxy('paper-button')
-class PaperButton extends HtmlElement with CustomElementProxyMixin, PolymerBase, IronA11yKeysBehavior, IronButtonState, IronControlState, PaperButtonBehavior {
+class PaperButton extends HtmlElement with CustomElementProxyMixin, PolymerBase, IronA11yKeysBehavior, IronButtonState, IronControlState, PaperRippleBehavior, PaperButtonBehavior {
   PaperButton.created() : super.created();
   factory PaperButton() => new Element.tag('paper-button');
 
   /// If true, the button should be styled with a shadow.
   bool get raised => jsElement[r'raised'];
   set raised(bool value) { jsElement[r'raised'] = value; }
 }