Currently, many performance tests in our devicelab uses --trace-startup to actually achieve the effect of --endless-trace-buffer (see [1]). Almost none of those tests uses such flag to trace the startup performance.

All our startup performance tests use flutter run --trace-startup (see [2]) which will close the app right after startup. On the contrary, flutter drive --trace-startup does not close the app after startup or after the entire drive run.

Shall we add --endless-trace-buffer option to flutter drive so we can use it instead of --trace-startup? That should reduce some confusions.