Remove barback from the repo.

sdk/lib/_internal/pub/test/dependency_computer/utils.dart

Index: sdk/lib/_internal/pub/test/dependency_computer/utils.dart
diff --git a/sdk/lib/_internal/pub/test/dependency_computer/utils.dart b/sdk/lib/_internal/pub/test/dependency_computer/utils.dart
index 06eb463299bb3f432c81a82ab17eb8decd5e7935..87ce96929075a7dad7a3dde98912de7fc8221761 100644
--- a/sdk/lib/_internal/pub/test/dependency_computer/utils.dart
+++ b/sdk/lib/_internal/pub/test/dependency_computer/utils.dart
@@ -96,7 +96,7 @@ PackageGraph _loadPackageGraph() {
   loadPackage(packageName) {
     if (packages.containsKey(packageName)) return;
     packages[packageName] = new Package.load(
-        packageName, p.join(pkgPath, packageName), systemCache.sources);
+        packageName, packagePath(packageName), systemCache.sources);
     for (var dep in packages[packageName].dependencies) {
       loadPackage(dep.name);
     }