Mark add or delete regions with darker colors

When intraline difference is enabled and a region is strictly an
insert or delete, use the darker intraline difference background
color on the region to help the edit stand-out against the lighter
common regions.  This fixes the oddity of newly inserted lines
appearing as though they were common, unless you looked at the old
side and noticed the grey background.

Change-Id: I26401f3dc99bcbca15886bb5454330e6b6947ed5
Signed-off-by: Shawn O. Pearce <sop@google.com>
1 file changed