Refactor Source and SourceRegistry.

test/dependency_computer/utils.dart

Index: test/dependency_computer/utils.dart
diff --git a/test/dependency_computer/utils.dart b/test/dependency_computer/utils.dart
index 2589bbca612673218a146f30c684636e7335b3c3..fc4aa5c0e89450a9695bdd9996ccaaeeb096922a 100644
--- a/test/dependency_computer/utils.dart
+++ b/test/dependency_computer/utils.dart
@@ -10,7 +10,6 @@ import 'package:pub/src/entrypoint.dart';
 import 'package:pub/src/io.dart';
 import 'package:pub/src/package.dart';
 import 'package:pub/src/package_graph.dart';
-import 'package:pub/src/source/path.dart';
 import 'package:pub/src/system_cache.dart';
 import 'package:pub/src/utils.dart';
 import 'package:scheduled_test/scheduled_test.dart';
@@ -78,10 +77,8 @@ PackageGraph _loadPackageGraph() {
   // Load the sandbox packages.
   var packages = {};
 
-  var systemCache = new SystemCache(p.join(sandboxDir, cachePath));
-  systemCache.sources
-      ..register(new PathSource())
-      ..setDefault('path');
+  var systemCache = new SystemCache(rootDir: p.join(sandboxDir, cachePath));
+  systemCache.sources.setDefault('path');
   var entrypoint = new Entrypoint(p.join(sandboxDir, appPath), systemCache);
 
   for (var package in listDir(sandboxDir)) {