As in https://ci.chromium.org/ui/p/flutter/builders/prod/Mac_ios%20draw_vertices_perf_ios__timeline_summary/3061/overview

Starting with aba1621.

There are a number of Impeller commits in that roll, but the device logs don't show any crashes, so I think this will need some local investigation.

@bdero @gaaclarke @jonahwilliams