message: Fix: Better guess for label slot
diff: @@ -250,6 +250,7 @@ addPredicate('paper-input-container', [
  {selector: '[prefix]', slot: 'prefix'},
  {selector: '[suffix]', slot: 'suffix'},
  {selector: '[add-on]', slot: 'add-on'},
  + {selector: 'label', slot: 'label'},
  {selector: '*', slot: 'input'},
  ]);
  