1. Today we paint backgrounds in Metrics box model on hover only - should be painted at all times for the reference.
2. Outlining boxes is highlight is wrong since outlines are outside the corresponding box regions. We've seen few reports on that + Firebug does not do borders for that reason.
Created attachment 107640 [details]
Comment on attachment 107640 [details]
Looks good, but it was more interactive when rectangle under cursor was highlighted in the metrics box on mouse hover. Would be nice to preserve that behavior.
Created attachment 108142 [details]
[Patch] for landing
Committed r95621: <http://trac.webkit.org/changeset/95621>