Found a potentially leaking cycle starting from a GC root:
./cycle_ptrs.h:51:5: blink::E (m_a) => blink::A
./cycle_ptrs.h:27:5: blink::A (m_b) => blink::B
./cycle_ptrs.h:36:3: blink::B (m_c) => blink::C
./cycle_ptrs.h:41:5: blink::C (m_d) => blink::D
./cycle_ptrs.h:46:5: blink::D (m_es) => blink::E