history: include search results in focus grid.

R=dmazzoni@chromium.org
BUG=419153
TEST=search, press tab a few times

Review URL: https://codereview.chromium.org/618833004

Cr-Commit-Position: refs/heads/master@{#297552}

chrome/browser/resources/history/history.js

@@ -1596,7 +1596,7 @@ HistoryView.prototype.displayResults_ = function(doneLoading) {
 };
 
 var focusGridRowSelector = [
-  '.day-results > .entry:not(.fade-out)',
+  ':-webkit-any(.day-results, .search-results) > .entry:not(.fade-out)',
   '.expand .grouped .entry:not(.fade-out)',
   '.site-domain-wrapper'
 ].join(', ');