fix imports link rel=stylesheet

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;
 
@@ skipping 86 matching lines @@
     var id = asset.id;
     return asset.readAsString().then((content) {
       return _parseHtml(content, id.path, transform.logger,
         checkDocType: options.isHtmlEntryPoint(id));
     });
   }
 
   Future<Document> readAsHtml(AssetId id, Transform transform) {
     var primaryId = transform.primaryInput.id;
     bool samePackage = id.package == primaryId.package;
-    var url = samePackage ? id.path
-        : assetUrlFor(id, primaryId, transform.logger, allowAssetUrl: true);
+    var url = spanUrlFor(id, transform);
     return transform.readInputAsString(id).then((content) {
       return _parseHtml(content, url, transform.logger,
         checkDocType: samePackage && options.isHtmlEntryPoint(id));
     });
   }
 
+  /**
+   * Gets the appropriate URL to use in a [Span] to produce messages
+   * (e.g. warnings) for users. This will attempt to format the URL in the most
+   * useful way:
+   *
+   * - If the asset is within the primary package, then use the [id.path],
+   *   the user will know it is a file from their own code.
+   * - If the asset is from another package, then use [assetUrlFor], this will
+   *   likely be a "package:" url to the file in the other package, which is
+   *   enough for users to identify where the error is.
+   */
+  String spanUrlFor(AssetId id, Transform transform) {
+    var primaryId = transform.primaryInput.id;
+    bool samePackage = id.package == primaryId.package;
+    return samePackage ? id.path
+        : assetUrlFor(id, primaryId, transform.logger, allowAssetUrl: true);
+  }
+
   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) {
+AssetId resolve(AssetId source, String url, TransformLogger logger, Span span,
+    {bool allowAbsolute: false}) {
   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: "$url"', span: span);
+    if (!allowAbsolute) {
+      logger.error('absolute paths not allowed: "$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);
   var topFolder = sourceSegments[0];
   var entryFolder = topFolder != 'lib' && topFolder != 'asset';
@@ skipping 83 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));
 }