package:observe fix various api issues

pkg/polymer/lib/src/build/runner.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.
 
 /**
  * Definitions used to run the polymer linter and deploy tools without using
  * pub serve or pub deploy.
  */
 library polymer.src.build.runner;
 
@@ skipping 132 matching lines @@
 void _initBarback(Barback barback, BarbackOptions options) {
   var assets = [];
   void addAssets(String package, String subDir) {
     for (var filepath in _listPackageDir(package, subDir, options)) {
       assets.add(new AssetId(package, filepath));
     }
   }
 
   for (var package in options.packageDirs.keys) {
     // There is nothing to do in the polymer package dependencies.
-    // However: in Polymer package *itself*, we need to replace ObservableMixin
-    // with ChangeNotifierMixin.
+    // However: in Polymer package *itself*, we need to replace Observable
+    // with ChangeNotifier.
     if (!options.transformPolymerDependencies &&
         _polymerPackageDependencies.contains(package)) continue;
     barback.updateTransformers(package, options.phases);
 
     // Notify barback to process anything under 'lib' and 'asset'.
     addAssets(package, 'lib');
     addAssets(package, 'asset');
   }
 
   // In case of the current package, include also 'web'.
@@ skipping 136 matching lines @@
 Future _copyFile(String inpath, String outpath) {
   _ensureDir(path.dirname(outpath));
   return new File(inpath).openRead().pipe(new File(outpath).openWrite());
 }
 
 /** Write contents of an [asset] into a file at [filepath]. */
 Future _writeAsset(String filepath, Asset asset) {
   _ensureDir(path.dirname(filepath));
   return asset.read().pipe(new File(filepath).openWrite());
 }