Update paper-checkbox to 0.5.4.

third_party/polymer/components-chromium/paper-checkbox/paper-checkbox-extracted.js

 
 
   Polymer('paper-checkbox', {
     
     /**
      * Fired when the checked state changes due to user interaction.
      *
      * @event change
      */
      
     /**
      * Fired when the checked state changes.
      *
      * @event core-change
      */
     
     toggles: true,
 
     checkedChanged: function() {
-      var cl = this.$.checkbox.classList;
-      cl.toggle('checked', this.checked);
-      cl.toggle('unchecked', !this.checked);
-      cl.toggle('checkmark', !this.checked);
-      cl.toggle('box', this.checked);
+      this.$.checkbox.classList.toggle('checked', this.checked);
       this.setAttribute('aria-checked', this.checked ? 'true': 'false');
+      this.$.checkmark.classList.toggle('hidden', !this.checked);
       this.fire('core-change');
     },
 
     checkboxAnimationEnd: function() {
-      var cl = this.$.checkbox.classList;
-      cl.toggle('checkmark', this.checked && !cl.contains('checkmark'));
-      cl.toggle('box', !this.checked && !cl.contains('box'));
+      var cl = this.$.checkmark.classList;
+      cl.toggle('hidden', !this.checked && cl.contains('hidden'));
     }
 
   });