Mac: Tweak content settings window.

Add "Features" label to source list.
xib change: Add some vertical space at the top of each tab, change outline view cell size to "small", hook up new outlet.

http://i.imgur.com/KGES6.png

BUG=45546
TEST=Content settings window still works: Current pane is still remembered, and opening the window from a bubble selects the right pane.

Review URL: http://codereview.chromium.org/2932009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@52199 0039d316-1c4b-4281-b951-d872f2087c98
7 files changed