[Mac] Select the previous node when the last cookie in the list is deleted.

Also recursively bubble up the delete if removing a child node will leave the
parent empty. Empty parents look awkward.

BUG=33320
TEST=See bug report. Partially covered by unit tests.

Review URL: http://codereview.chromium.org/1598001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@43157 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed