Revert "Add Resource class. Currently unimplemented."

runtime/lib/core_patch.dart

Index: runtime/lib/core_patch.dart
diff --git a/runtime/lib/core_patch.dart b/runtime/lib/core_patch.dart
index 0358cc28ddd79b8ecfe4959164b4572596cc7245..2a45ae708efed16d1b8b4276978c5a8cd8b28de5 100644
--- a/runtime/lib/core_patch.dart
+++ b/runtime/lib/core_patch.dart
@@ -205,27 +205,3 @@ class _SyncIterator implements Iterator {
     }
   }
 }
-
-patch class Resource {
-  /* patch */ const factory Resource(String uri) = _Resource;
-}
-
-class _Resource implements Resource {
-  final String _location;
-
-  const _Resource(String uri) : _location = uri;
-
-  Uri get uri => Uri.base.resolve(_location);
-
-  Stream<List<int>> openRead() {
-    throw new UnimplementedError("openRead");
-  }
-
-  Future<List<int>> readAsBytes() {
-    throw new UnimplementedError("readAsBytes");
-  }
-
-  Future<String> readAsString({Encoding encoding}) {
-    throw new UnimplementedError("readAsString");
-  }
-}