[GOM] Improve the display of the roll information

The current UI was racy and would output the last roll
and current roll in random order. This change fixes this
and puts the roll information to a new line, so that it
stands out from the bot information.

Review URL: https://codereview.chromium.org/314913002

git-svn-id: svn://svn.chromium.org/blink/trunk@175525 bbb929c8-8fbe-4397-9dbb-9b2b20218538