1 In file included from register_weak_members_template.cpp:5: 2 ./register_weak_members_template.h:19:3: warning: [blink-gc] Class 'HasUntracedWeakMembers' has untraced fields that require tracing. 3 void Trace(Visitor* visitor) { 4 ^ 5 ./register_weak_members_template.h:28:3: note: [blink-gc] Untraced field 'x_' declared here: 6 WeakMember<X> x_; 7 ^ 8 1 warning generated. 9