Temporarily Making Server-Side NTP Recommendations Use LINK Transition Instead of...

Temporarily Making Server-Side NTP Recommendations Use LINK Transition Instead of AUTO_BOOKMARK

Previously "NTP clicks" (i.e., navigations on NTP suggestions) use AUTO_BOOKMARK transition type. Eventually we want to create a new transition type, but right now AUTO_BOOKMARK ambiguates NTP clicks with bookmark usage.  To prevent this, this CL make NTP clicks for *server-side suggestions* a LINK transition type.  This partially reverts the changes for https://chromiumcodereview.appspot.com/178253008/ .

Important: NTP clicks for client-side recommendations (i.e., Most Visited) remains at AUTO_BOOKMARK, as to not interfere with existing behavior in chain start detection.

BUG=
NOTRY=true

Review URL: https://codereview.chromium.org/274143002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@269658 0039d316-1c4b-4281-b951-d872f2087c98