fix: work-around compile issue on mac
fix: work-around compile issue on mac

Clang on mac complains about `0` being used instead of `nullptr`.

Change-Id: Ie9ee045aaddfe53ecb342e5f7e3a2d871dbe1dca
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto