[Mac] Implement the avatar menu bubble.
This also makes a change to AvatarMenuModel such that it no longer notifies its
delegate that the model changed at time of construction. It will now only notify
after any other change occurs. This requires clients to now schedule a layout
themselves after constructing the model.
BUG=60105
TEST=Run with --multi-profiles. Click on avatar. See bubble menu.
Review URL: http://codereview.chromium.org/7647002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@96851 0039d316-1c4b-4281-b951-d872f2087c98
14 files changed
