Removed wall_clock_time_in_us field.

Bug: v8:11109
Change-Id: Ib3efa74fc741b793ef064c1d12ca1797be3a10c1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2550280Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Sara Tang <sartang@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#71386}