Switch polymer's build.dart to use the new linter. This CL does the following

pkg/polymer/lib/src/transform/polyfill_injector.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Final phase of the polymer transformation: includes any additional polyfills
  * that may needed by the deployed app.
  */
 library polymer.src.transform.polyfill_injector;
 
 import 'dart:async';
 
 import 'package:barback/barback.dart';
 import 'package:html5lib/dom.dart' show Document, Node, DocumentFragment;
 import 'package:html5lib/parser.dart' show parseFragment;
 import 'common.dart';
 
 /**
  * Ensures that any scripts and polyfills needed to run a polymer application
  * are included. For example, this transformer will ensure that there is a
  * script tag that loads the shadow_dom polyfill and interop.js (used for the
  * css shimming).
  */
-class PolyfillInjector extends Transformer {
+class PolyfillInjector extends Transformer with PolymerTransformer {
+  final TransformOptions options;
+
+  PolyfillInjector(this.options);
+
   /** Only run on entry point .html files. */
   Future<bool> isPrimary(Asset input) =>
-      new Future.value(isPrimaryHtml(input.id));
+      new Future.value(options.isHtmlEntryPoint(input.id));
 
   Future apply(Transform transform) {
     return readPrimaryAsHtml(transform).then((document) {
       bool shadowDomFound = false;
       bool jsInteropFound = false;
       bool pkgJsInteropFound = false;
       bool dartScriptTags = false;
 
       for (var tag in document.queryAll('script')) {
         var src = tag.attributes['src'];
@@ skipping 39 matching lines @@
             '<script src="packages/shadow_dom/shadow_dom.debug.js"></script>\n'));
       }
 
       transform.addOutput(
           new Asset.fromString(transform.primaryInput.id, document.outerHtml));
     });
   }
 }
 
 final _shadowDomJS = new RegExp(r'shadow_dom\..*\.js', caseSensitive: false);