Update charted to 0.4.8 and roll

packages/package_config/lib/discovery.dart

Index: packages/package_config/lib/discovery.dart
diff --git a/packages/package_config/lib/discovery.dart b/packages/package_config/lib/discovery.dart
index 8e42af79d78fe213b9ec5d1f4ae9d034e99eb0d0..4c09eecfbabcde5ca56b1a1e086bbb7f4dbdc1dc 100644
--- a/packages/package_config/lib/discovery.dart
+++ b/packages/package_config/lib/discovery.dart
@@ -28,22 +28,21 @@ import "src/packages_io_impl.dart";
 /// resolution file, for example one specified using a `--packages`
 /// command-line parameter.
 Future<Packages> loadPackagesFile(Uri packagesFile,
-                                  {Future<List<int>> loader(Uri uri)}) {
+    {Future<List<int>> loader(Uri uri)}) async {
   Packages parseBytes(List<int> bytes) {
     Map<String, Uri> packageMap = pkgfile.parse(bytes, packagesFile);
     return new MapPackages(packageMap);
   }
   if (packagesFile.scheme == "file") {
     File file = new File.fromUri(packagesFile);
-    return file.readAsBytes().then(parseBytes);
+    return parseBytes(await file.readAsBytes());
   }
   if (loader == null) {
-    return _httpGet(packagesFile).then(parseBytes);
+    return parseBytes(await _httpGet(packagesFile));
   }
-  return loader(packagesFile).then(parseBytes);
+  return parseBytes(await loader(packagesFile));
 }
 
-
 /// Create a [Packages] object for a package directory.
 ///
 /// The [packagesDir] URI should refer to a directory.
@@ -63,7 +62,6 @@ Packages getPackagesDirectory(Uri packagesDir) {
   return new NonFilePackagesDirectoryPackages(packagesDir);
 }
 
-
 /// Discover the package configuration for a Dart script.
 ///
 /// The [baseUri] points to either the Dart script or its directory.
@@ -93,7 +91,7 @@ Packages getPackagesDirectory(Uri packagesDir) {
 /// The content should be a UTF-8 encoded `.packages` file, and must return an
 /// error future if loading fails for any reason.
 Future<Packages> findPackages(Uri baseUri,
-                              {Future<List<int>> loader(Uri unsupportedUri)}) {
+    {Future<List<int>> loader(Uri unsupportedUri)}) {
   if (baseUri.scheme == "file") {
     return new Future<Packages>.sync(() => findPackagesFromFile(baseUri));
   } else if (loader != null) {
@@ -191,17 +189,19 @@ Packages findPackagesFromFile(Uri fileBaseUri) {
 /// of the requested `.packages` file as bytes, which will be assumed to be
 /// UTF-8 encoded.
 Future<Packages> findPackagesFromNonFile(Uri nonFileUri,
-                                         {Future<List<int>> loader(Uri name)}) {
+    {Future<List<int>> loader(Uri name)}) async {
   if (loader == null) loader = _httpGet;
   Uri packagesFileUri = nonFileUri.resolve(".packages");
-  return loader(packagesFileUri).then((List<int> fileBytes) {
+
+  try {
+    List<int> fileBytes = await loader(packagesFileUri);
     Map<String, Uri> map = pkgfile.parse(fileBytes, packagesFileUri);
     return new MapPackages(map);
-  }, onError: (_) {
+  } catch (_) {
     // Didn't manage to load ".packages". Assume a "packages/" directory.
     Uri packagesDirectoryUri = nonFileUri.resolve("packages/");
     return new NonFilePackagesDirectoryPackages(packagesDirectoryUri);
-  });
+  }
 }
 
 /// Fetches a file over http.