Pass a package root to spawned isolates in pub.

sdk/lib/_internal/pub_generated/lib/src/barback/rewrite_import_transformer.dart

Index: sdk/lib/_internal/pub_generated/lib/src/barback/rewrite_import_transformer.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/barback/rewrite_import_transformer.dart b/sdk/lib/_internal/pub_generated/lib/src/barback/rewrite_import_transformer.dart
deleted file mode 100644
index bea129efbedb2acd2bd9960cac5ea6294d512c49..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/lib/src/barback/rewrite_import_transformer.dart
+++ /dev/null
@@ -1,26 +0,0 @@
-library pub.rewrite_import_transformer;
-import 'dart:async';
-import 'package:barback/barback.dart';
-import '../dart.dart';
-class RewriteImportTransformer extends Transformer {
-  String get allowedExtensions => '.dart';
-  Future apply(Transform transform) {
-    return transform.primaryInput.readAsString().then((contents) {
-      var directives =
-          parseImportsAndExports(contents, name: transform.primaryInput.id.toString());
-      var buffer = new StringBuffer();
-      var index = 0;
-      for (var directive in directives) {
-        var uri = Uri.parse(directive.uri.stringValue);
-        if (uri.scheme != 'package') continue;
-        buffer
-            ..write(contents.substring(index, directive.uri.literal.offset))
-            ..write('"/packages/${uri.path}"');
-        index = directive.uri.literal.end;
-      }
-      buffer.write(contents.substring(index, contents.length));
-      transform.addOutput(
-          new Asset.fromString(transform.primaryInput.id, buffer.toString()));
-    });
-  }
-}