Make probe::frameScheduledNavigation not depend on ScheduledNavigation

I'm in the process of removing ScheduledNavigation, but we still need this
probe.

Also, add back in the probe for reloads, which no longer go through
ScheduledNavigation.

Bug: 914587
Change-Id: Ie0c128a4f692bcfe05a62df6f214226260d45dfd
Reviewed-on: https://chromium-review.googlesource.com/c/1383141
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Nate Chapin <japhet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#617652}
14 files changed