We absolutely should incur the overhead only when the trace recording is enabled. You can do this easily by following the pattern in InspectorInstrumentation.h -- basically, only create TracedValue when arguments to trace macro are being evaluated, just by extracting creation/population into the function.

That's great to hear! I am hoping to find some next next Q to write perf tests so these types of regressions will be easier to spot.

Thanks for the quick reply.

This is a great catch - thank you! I'll fix this asap. How did you do the profiling?

This is on my linux desktop using the linux perf tool.

https://codereview.chromium.org/2537143005/ fixes this. Can this be merged in M56? 

This regression was new in M56 and was introduced by https://codereview.chromium.org/2444783002/

Your change meets the bar and is auto-approved for M56 (branch: 2924)

Merged here: https://chromium.googlesource.com/chromium/src/+/4e24008e8258b873785bff76b3b308f31e64f33b