Move banner counting logic much later in the pipeline

The banner can fail to be shown for any number of reasons,
from a user navigation to a failed icon fetch.  Record that
the banner could have been shown only right before the
infobar is created.

This fixes situations where a user already had a native app
installed and the website requested a banner for it, which
permanently fills a slot in app dictionary for the site --
even if the Play Store tells the AppBannerManager that the
app is installed and no banner should be shown.

BUG=453170,452825

Review URL: https://codereview.chromium.org/905913002

Cr-Commit-Position: refs/heads/master@{#315193}
1 file changed