- Fix build: Make sure that external methods are patched in dart2js.

sdk/lib/_internal/js_runtime/lib/isolate_patch.dart

Index: sdk/lib/_internal/js_runtime/lib/isolate_patch.dart
diff --git a/sdk/lib/_internal/js_runtime/lib/isolate_patch.dart b/sdk/lib/_internal/js_runtime/lib/isolate_patch.dart
index 85b30b1a6311b7f03ee467279adba9613842f1f2..8b8d023e24c9e280d6f929ba486586594aa7eb72 100644
--- a/sdk/lib/_internal/js_runtime/lib/isolate_patch.dart
+++ b/sdk/lib/_internal/js_runtime/lib/isolate_patch.dart
@@ -20,6 +20,16 @@ class Isolate {
   static Isolate get current => _currentIsolateCache;
 
   @patch
+  static Future<Uri> get packageRoot {
+    throw new UnsupportedError("Isolate.packageRoot");
+  }
+
+  @patch
+  static Future<Map<String, Uri>> get packageMap {
+    throw new UnsupportedError("Isolate.packageMap");
+  }
+
+  @patch
   static Future<Isolate> spawn(void entryPoint(message), var message,
                                {bool paused: false, bool errorsAreFatal,
                                 SendPort onExit, SendPort onError}) {