optional_gc_object.cpp:10:24: warning: [blink-gc] Disallowed construction of 'Optional<blink::Base>' found; 'Base' is a garbage-collected type. optional cannot hold garbage-collected objects.
  base::Optional<Base> optional_base;
                       ^~~~~~~~~~~~~
optional_gc_object.cpp:13:27: warning: [blink-gc] Disallowed construction of 'Optional<blink::Derived>' found; 'Derived' is a garbage-collected type. optional cannot hold garbage-collected objects.
  base::Optional<Derived> optional_derived;
                          ^~~~~~~~~~~~~~~~
optional_gc_object.cpp:16:7: warning: [blink-gc] Disallowed construction of 'Optional<blink::Base>' found; 'Base' is a garbage-collected type. optional cannot hold garbage-collected objects.
  new base::Optional<Base>;
      ^~~~
3 warnings generated.