[Mac] Use the ExtensionToolbarModel for ordering of the Browser Actions. Prep for drag and drop for re-ordering.
Also fixes crashers where if you tried to disable an extension via its context menu while an incognito window was key, boom.

BUG=26990
TEST=none
Review URL: http://codereview.chromium.org/595017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@38632 0039d316-1c4b-4281-b951-d872f2087c98
9 files changed