M73: Revert "[EventTiming] Ship First Input Timing on main frames"

This reverts commit 1ff422d8a30a34713c652508fc170f75120460a1 for M73.
Original CL:
https://chromium-review.googlesource.com/c/chromium/src/+/1368826

Bug: 927380, 823744, 841224

Change-Id: I0298780547f9a5de59a3e7bd9dcacff84fe17b8b
Reviewed-on: https://chromium-review.googlesource.com/c/1448695
Reviewed-by: Timothy Dresser <tdresser@chromium.org>
Cr-Commit-Position: refs/branch-heads/3683@{#129}
Cr-Branched-From: e51029943e0a38dd794b73caaf6373d5496ae783-refs/heads/master@{#625896}
9 files changed