Update charted to 0.4.8 and roll

packages/package_config/lib/packages.dart

 // Copyright (c) 2015, 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.
 
 library package_config.packages;
 
 import "src/packages_impl.dart";
 
 /// A package resolution strategy.
 ///
 /// Allows converting a `package:` URI to a different kind of URI.
 ///
 /// May also allow listing the available packages and converting
 /// to a `Map<String, Uri>` that gives the base location of each available
 /// package. In some cases there is no way to find the available packages,
 /// in which case [packages] and [asMap] will throw if used.
 /// One such case is if the packages are resolved relative to a
 /// `packages/` directory available over HTTP.
 abstract class Packages {
-
   /// A [Packages] resolver containing no packages.
   ///
   /// This constant object is returned by [find] above if no
   /// package resolution strategy is found.
   static const Packages noPackages = const NoPackages();
 
   /// Resolve a package URI into a non-package URI.
   ///
   /// Translates a `package:` URI, according to the package resolution
   /// strategy, into a URI that can be loaded.
@@ skipping 19 matching lines @@
   ///
   /// Returns a map from package name to a base URI.
   /// The [resolve] method will resolve a package URI with a specific package
   /// name to a path extending the base URI that this map gives for that
   /// package name.
   ///
   /// Some `Packages` objects are unable to find the package names,
   /// and calling `asMap` on such a `Packages` object will throw.
   Map<String, Uri> asMap();
 }