Adds a script that runs a v8.browsing_desktop story a number of times
and extracts the runtime call stats as either a table or csv.

Change-Id: I4e93cd120b3496410517a2f26547b954fc59d92a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1953343
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65353}