- Add getters for the current packageRoot or packageMap.

runtime/lib/isolate_patch.dart

Index: runtime/lib/isolate_patch.dart
diff --git a/runtime/lib/isolate_patch.dart b/runtime/lib/isolate_patch.dart
index daaaf9729f1444dffe5bd40ce83e7a2a53809c99..438d4cbe314580c653721947519cf9473a85bcb2 100644
--- a/runtime/lib/isolate_patch.dart
+++ b/runtime/lib/isolate_patch.dart
@@ -275,6 +275,22 @@ patch class Isolate {
 
   /* patch */ static Isolate get current => _currentIsolate;
 
+  /* patch */ static Future<Uri> get packageRoot {
+    var hook = VMLibraryHooks.getPackageRoot;
+    if (hook == null) {
+      throw new UnimplementedError("Isolate.packageRoot");
+    }
+    return hook();
+  }
+
+  /* patch */ static Future<Map<String, Uri>> get packageMap {
+    var hook = VMLibraryHooks.getPackageMap;
+    if (hook == null) {
+      throw new UnimplementedError("Isolate.packageMap");
+    }
+    return hook();
+  }
+
   /* patch */ static Future<Isolate> spawn(
       void entryPoint(message), var message,
       {bool paused: false, bool errorsAreFatal,