Fix equality invocation on native objects

tests/lib_strong/html/client_rect_test.dart

Index: tests/lib_strong/html/client_rect_test.dart
diff --git a/tests/lib_strong/html/client_rect_test.dart b/tests/lib_strong/html/client_rect_test.dart
index 526e01145746a536bae443e7a2679b969cc44cd9..983be6b11afe717c6d4afa22f49333e6c1cc09cd 100644
--- a/tests/lib_strong/html/client_rect_test.dart
+++ b/tests/lib_strong/html/client_rect_test.dart
@@ -23,4 +23,10 @@ main() {
     var rects = range.getClientRects();
     expect(rects, isRectList);
   });
+
+  test("ClientRect ==", () {
+    var rect1 = document.body.getBoundingClientRect();
+    var rect2 = document.body.getBoundingClientRect();
+    expect(rect1, equals(rect2));
+  });
 }