Build with filesystem_clock.cpp across platforms

An update to the internal repo in components/optimization_guide/internal
now requires this functionality across most platforms.

Change-Id: I13844ccbe025a5b933e367f8658fd4bd4289448e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7871364
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1637298}
NOKEYCHECK=True
GitOrigin-RevId: 1aecdd09d5a2c0c47a416c7e91a9e0c3d23ab64c