Revert of Reland: mus: Add views_mus_interactive_ui_tests target

ui/views/test/scoped_views_test_helper.h

Index: ui/views/test/scoped_views_test_helper.h
diff --git a/ui/views/test/scoped_views_test_helper.h b/ui/views/test/scoped_views_test_helper.h
index b3778538204b94b46c0f8da9430b85faa2b01269..2b30a3395ffd87ce97748795207e9d9cc6784160 100644
--- a/ui/views/test/scoped_views_test_helper.h
+++ b/ui/views/test/scoped_views_test_helper.h
@@ -39,6 +39,8 @@
 
   TestViewsDelegate* views_delegate() { return views_delegate_.get(); };
 
+  bool IsMus() const;
+
  private:
   std::unique_ptr<TestViewsDelegate> views_delegate_;
   std::unique_ptr<ViewsTestHelper> test_helper_;