GitLab

Normalize the score across all anchor elements. This makes
it simpler to use anchor element score when predicting the
next navigation when there are many anchors on the webpage,
and all of them may have high score.

Also, includes minor cleanups where some of the variables
are added to the header file. These will be used in the next CL.

Change-Id: Iad914682ef6d96c1b4d3cab040b555a6723f05de
Bug: 903945
TBR: ryansturm@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/1328561
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607020}