Don't focus the location bar in a phishy situation.

      There is logic to focus the location bar for editing if the URL is about:blank.
However, if the page transition type is PAGE_TRANSITION_LINK, bypass that logic;
it's not really a blank page. This avoids a phishy edge case with window.open.

BUG=567445

Review URL: https://codereview.chromium.org/1678233003

Cr-Commit-Position: refs/heads/master@{#379396}