update elements and fix some bugs

lib/paper_checked_element_behavior.dart

+// DO NOT EDIT: auto-generated with `pub run custom_element_apigen:update`
+
+/// Dart API for the polymer element `paper_checked_element_behavior`.
+@HtmlImport('paper_checked_element_behavior_nodart.html')
+library polymer_elements.lib.src.paper_behaviors.paper_checked_element_behavior;
+
+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_inky_focus_behavior.dart';
+import 'iron_button_state.dart';
+import 'iron_a11y_keys_behavior.dart';
+import 'iron_control_state.dart';
+import 'paper_ripple_behavior.dart';
+import 'iron_checked_element_behavior.dart';
+import 'iron_form_element_behavior.dart';
+import 'iron_validatable_behavior.dart';
+
+/// Use `Polymer.PaperCheckedElementBehavior` to implement a custom element
+/// that has a `checked` property similar to `Polymer.IronCheckedElementBehavior`
+/// and is compatible with having a ripple effect.
+@BehaviorProxy(const ['Polymer', 'PaperCheckedElementBehavior'])
+abstract class PaperCheckedElementBehavior implements CustomElementProxyMixin, PaperInkyFocusBehavior, IronCheckedElementBehavior {
+}