In dart-lang/sdk#49119 it was found that the dart profiler can aggravate the paging in of code in the VM which can cause the wall time spent in symbols to inflate to 2x. For profile builds this can skew benchmarks that rely on wall time. We should add a flag to flutter tool that allows us to launch the process without the dart profiler running.

In practice I think benchmarks usually repeat tests, like //dev/benchmarks/microbenchmarks/lib/stocks/build_bench.dart, so that the increased cost of the first run would get averaged out. I'm not sure there is a need for this flag beyond manually profiling apps. It's particularly acute when using DevTools and looking at the Timeline events since the CPU time for symbols isn't visible there.

Related issue: #104656

cc @kenzieschmoll @dnfield