webui fixes for 0.8.9

lib/src/info.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.
 
 /**
  * Datatypes holding information extracted by the analyzer and used by later
  * phases of the compiler.
  */
 library web_ui.src.info;
 
 import 'dart:collection' show SplayTreeMap, LinkedHashMap;
 
 import 'package:analyzer_experimental/src/generated/ast.dart';
-import 'package:csslib/parser.dart' as css;
 import 'package:csslib/visitor.dart';
 import 'package:html5lib/dom.dart';
 import 'package:source_maps/span.dart' show Span;
 
 import 'dart_parser.dart' show DartCodeInfo;
-import 'files.dart';
 import 'messages.dart';
 import 'summary.dart';
 import 'utils.dart';
 
 /**
  * Information for any library-like input. We consider each HTML file a library,
  * and each component declaration a library as well. Hence we use this as a base
  * class for both [FileInfo] and [ComponentInfo]. Both HTML files and components
  * can have .dart code provided by the user for top-level user scripts and
  * component-level behavior code. This code can either be inlined in the HTML
@@ skipping 230 matching lines @@
     }
   }
 
   String toString() => '#<ComponentInfo $tagName '
       '${inlinedCode != null ? "inline" : "from ${dartCodeUrl.resolvedPath}"}>';
 }
 
 /** Base tree visitor for the Analyzer infos. */
 class InfoVisitor {
   visit(info) {
-    if (info == null) return;
+    if (info == null) return null;
     if (info is TemplateInfo) {
       return visitTemplateInfo(info);
     } else if (info is ElementInfo) {
       return visitElementInfo(info);
     } else if (info is TextInfo) {
       return visitTextInfo(info);
     } else if (info is ComponentInfo) {
       return visitComponentInfo(info);
     } else if (info is FileInfo) {
       return visitFileInfo(info);
@@ skipping 391 matching lines @@
     return new UrlInfo(url, target, span);
   }
 
   bool operator ==(UrlInfo other) =>
       url == other.url && resolvedPath == other.resolvedPath;
 
   int get hashCode => resolvedPath.hashCode;
 
   String toString() => "#<UrlInfo url: $url, resolvedPath: $resolvedPath>";
 }