The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e0be759f29bd8acd4b83da1aa3e49c645da01ef3

commit e0be759f29bd8acd4b83da1aa3e49c645da01ef3
Author: ryansturm <ryansturm@chromium.org>
Date: Tue Dec 20 22:45:19 2016

Seperate reloads when reporting previews infobar dismissal

When the previews infobar is dismissed, it would be valuable to track
reloads differently from new navigations. Reloads are not treated as
opt outs by the blacklisting policy, so the page could be served as a new LoFi page or LitePage after a reload
(offline previews are specifically prevented from being shown on any
reload however).

If the user dismisses the infobar and then reloads, this will only be captured as the user dismissing the infobar.

BUG= 672634 

Review-Url: https://codereview.chromium.org/2557113004
Cr-Commit-Position: refs/heads/master@{#439895}

[modify] https://crrev.com/e0be759f29bd8acd4b83da1aa3e49c645da01ef3/chrome/browser/previews/previews_infobar_delegate.cc
[modify] https://crrev.com/e0be759f29bd8acd4b83da1aa3e49c645da01ef3/chrome/browser/previews/previews_infobar_delegate.h
[modify] https://crrev.com/e0be759f29bd8acd4b83da1aa3e49c645da01ef3/chrome/browser/previews/previews_infobar_delegate_unittest.cc
[modify] https://crrev.com/e0be759f29bd8acd4b83da1aa3e49c645da01ef3/tools/metrics/histograms/histograms.xml