[third_party] add polymer 1.2.3

polymer_1.2.3/bower_components/iron-validatable-behavior/demo/cats-only.html

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@@ skipping 26 matching lines @@
         return this.validateObject(values);
       } else {
         var value = Array.isArray(values) ? values.join('') : values;
         return value.match(/^(c|ca|cat|cats)?$/) !== null;
       }
     }
 
   });
 
 </script>