Removing polymer-specific code from barback runner

pkg/polymer/lib/src/build/common.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.
 
 /** Common methods used by transfomers. */
 library polymer.src.build.common;
 
 import 'dart:async';
 import 'dart:math' show min, max;
 
 import 'package:barback/barback.dart';
 import 'package:html5lib/dom.dart' show Document;
 import 'package:html5lib/parser.dart' show HtmlParser;
 import 'package:path/path.dart' as path;
+import 'package:observe/transformer.dart' show ObservableTransformer;
 import 'package:source_maps/span.dart' show Span;
 
 /**
  * Parses an HTML file [contents] and returns a DOM-like tree. Adds emitted
  * error/warning to [logger].
  */
 Document _parseHtml(String contents, String sourcePath, TransformLogger logger,
     {bool checkDocType: true}) {
   // TODO(jmesserly): make HTTP encoding configurable
   var parser = new HtmlParser(contents, encoding: 'utf8', generateSpans: true,
@@ skipping 85 matching lines @@
         checkDocType: samePackage && options.isHtmlEntryPoint(id));
     });
   }
 
   Future<bool> assetExists(AssetId id, Transform transform) =>
       transform.getInput(id).then((_) => true).catchError((_) => false);
 
   String toString() => 'polymer ($runtimeType)';
 }
 
+/** Transformer phases which should be applied to the Polymer package. */
+List<List<Transformer>> get phasesForPolymer =>
+    [[new ObservableTransformer(['lib/src/instance.dart'])]];
+
 /**
  * Create an [AssetId] for a [url] seen in the [source] asset. By default this
  * is used to resolve relative urls that occur in HTML assets, including
  * cross-package urls of the form "packages/foo/bar.html". Dart-style "package:"
  * urls are not resolved unless [source] is Dart file (has a .dart extension).
  */
 // TODO(sigmund): delete once this is part of barback (dartbug.com/12610)
 AssetId resolve(AssetId source, String url, TransformLogger logger, Span span) {
   if (url == null || url == '') return null;
   var uri = Uri.parse(url);
   var urlBuilder = path.url;
   if (uri.host != '' || uri.scheme != '' || urlBuilder.isAbsolute(url)) {
     if (source.extension == '.dart' && uri.scheme == 'package') {
       var index = uri.path.indexOf('/');
       if (index != -1) {
         return new AssetId(uri.path.substring(0, index),
             'lib${uri.path.substring(index)}');
       }
-    } 
+    }
 
     logger.error('absolute paths not allowed: "$url"', span: span);
     return null;
   }
 
   var targetPath = urlBuilder.normalize(
       urlBuilder.join(urlBuilder.dirname(source.path), url));
   var segments = urlBuilder.split(targetPath);
   var sourceSegments = urlBuilder.split(source.path);
   assert (sourceSegments.length > 0);
@@ skipping 85 matching lines @@
   return builder.relative(builder.join('/', id.path),
       from: builder.join('/', builder.dirname(sourceId.path)));
 }
 
 
 /** Convert system paths to asset paths (asset paths are posix style). */
 String _systemToAssetPath(String assetPath) {
   if (path.Style.platform != path.Style.windows) return assetPath;
   return path.posix.joinAll(path.split(assetPath));
 }