Enables codegen support in polymer

pkg/polymer/lib/transformer.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.
 
 /// Transfomer used for pub-serve and pub-deploy.
 library polymer.transformer;
 
 import 'package:barback/barback.dart';
 import 'package:observe/transformer.dart';
 
@@ skipping 10 matching lines @@
 ///   * Inline imported html files
 ///   * Combine scripts from multiple files into a single script tag
 ///   * Inject extra polyfills needed to run on all browsers.
 ///
 /// At the end of these phases, this tranformer produces a single entrypoint
 /// HTML file with a single Dart script that can later be compiled with dart2js.
 class PolymerTransformerGroup implements TransformerGroup {
   final Iterable<Iterable> phases;
 
   PolymerTransformerGroup(TransformOptions options)
-      : phases = _createDeployPhases(options);
+      : phases = createDeployPhases(options);
 
   PolymerTransformerGroup.asPlugin(BarbackSettings settings)
       : this(_parseSettings(settings));
 }
 
 TransformOptions _parseSettings(BarbackSettings settings) {
   var args = settings.configuration;
   bool releaseMode = settings.mode == BarbackMode.RELEASE;
   bool jsOption = args['js'];
   bool csp = args['csp'] == true; // defaults to false
@@ skipping 20 matching lines @@
   if (error) {
     print('Invalid value for "entry_points" in the polymer transformer.');
   }
   return entryPoints;
 }
 
 /// Create deploy phases for Polymer. Note that inlining HTML Imports
 /// comes first (other than linter, if [options.linter] is enabled), which
 /// allows the rest of the HTML-processing phases to operate only on HTML that
 /// is actually imported.
-List<List<Transformer>> _createDeployPhases(TransformOptions options) {
+List<List<Transformer>> createDeployPhases(
+    TransformOptions options, {String sdkDir}) {
   var phases = options.lint ? [[new Linter(options)]] : [];
   return phases..addAll([
     [new ImportInliner(options)],
     [new ObservableTransformer()],
-    [new ScriptCompactor(options)],
+    [new ScriptCompactor(options, sdkDir: sdkDir)],
     [new PolyfillInjector(options)],
     [new BuildFilter(options)]
   ]);
 }