Cleanup: base::TimeTicks variables are named to be *_time.

This is a follow up of:
https://chromium-review.googlesource.com/c/chromium/src/+/5508411

To make the naming rule consistent, this CL renamed base::TimeTicks type
variables to have "_time" suffix.

Bug: 333952112
Change-Id: I3fbb621f7142e8731820ff752ba702171c9e05d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5527156
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Minoru Chikamune <chikamune@chromium.org>
Reviewed-by: Shunya Shishido <sisidovski@chromium.org>
Auto-Submit: Yoshisato Yanagisawa <yyanagisawa@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1298532}