This method only resets the base score for a URL. It does not affect the
bonus score that an origin might receive, e.g. from being installed to
the user's desktop or homescreen. This means that getting the score of
an origin immediately after resetting it might return an unexpected
number.

This CL renames the method and adds a comment explicitly calling out the
potential difference.

BUG=699381
TBR=bauerb@chromium.org
TBR=dbeam@chromium.org

Review-Url: https://codereview.chromium.org/2735333002
Cr-Commit-Position: refs/heads/master@{#455918}