fields_require_tracing.cpp:9:1: warning: [blink-gc] Class 'PartObject' has untraced fields that require tracing. void PartObject::Trace(Visitor* visitor) { ^ ./fields_require_tracing.h:29:5: note: [blink-gc] Untraced field 'm_obj1' declared here: Member m_obj1; ^ ./fields_require_tracing.h:31:5: note: [blink-gc] Untraced field 'm_obj3' declared here: Member m_obj3; ^ fields_require_tracing.cpp:16:1: warning: [blink-gc] Class 'PartBObject' has untraced fields that require tracing. void PartBObject::Trace(Visitor* visitor) { ^ ./fields_require_tracing.h:20:5: note: [blink-gc] Untraced field 'm_set' declared here: HeapHashSet m_set; ^ fields_require_tracing.cpp:21:1: warning: [blink-gc] Class 'HeapObject' has untraced fields that require tracing. void HeapObject::Trace(Visitor* visitor) { ^ ./fields_require_tracing.h:40:5: note: [blink-gc] Untraced field 'm_part' declared here: PartObject m_part; ^ 3 warnings generated.