Update charted to 0.4.8 and roll

packages/csslib/lib/css.dart

Index: packages/csslib/lib/css.dart
diff --git a/packages/csslib/lib/css.dart b/packages/csslib/lib/css.dart
index 590e8351c3130553368462f5a48a4938e8026fc2..e7ef5344346dde554414289a69526bc16638546e 100644
--- a/packages/csslib/lib/css.dart
+++ b/packages/csslib/lib/css.dart
@@ -10,9 +10,8 @@ import 'package:path/path.dart' as path;
 import 'package:source_span/source_span.dart';
 
 import 'parser.dart';
-import 'visitor.dart';
 import 'src/messages.dart';
-import 'src/options.dart';
+import 'visitor.dart';
 
 void main(List<String> arguments) {
   // TODO(jmesserly): fix this to return a proper exit code
@@ -39,7 +38,7 @@ void _compile(String inputPath, bool verbose) {
     var file = new SourceFile(contents, url: path.toUri(inputPath));
 
     // Parse the CSS.
-    var tree = _time(
+    StyleSheet tree = _time(
         'Parse $filename', () => new Parser(file, contents).parse(), verbose);
 
     _time('Analyzer $filename', () => new Analyzer([tree], messages), verbose)
@@ -76,8 +75,6 @@ void _printMessage(String message, int duration) {
   buf.write(' -- ');
   if (duration < 10) buf.write(' ');
   if (duration < 100) buf.write(' ');
-  buf
-    ..write(duration)
-    ..write(' ms');
+  buf..write(duration)..write(' ms');
   print(buf.toString());
 }