For a reviewer it is important to notice that he is reviewing a merge commit. Normally this should be obvious by the commit message, but there may be merge commits with bad commit messages. Highlight merge commits by displaying an icon for them. The icon is taken from the Tango Icon Library [1]. [1] http://tango.freedesktop.org/Tango_Icon_Library Change-Id: I510909a3b146f448492ee11da3c8b80160dec715