Removes 'GetDefaultProfile' from MessageCenterSettingsController.

Instead, the profile will be added after the for-loop because it
doesn't appear in the profile cache.

Also, the Rebuild should be stopped if the created profile is
off-the-record. Otherwise, GetOffTheRecordProfile() in Rebuild
will emit PROFILE_CREATED event.

BUG=322682
R=skuhne@chromium.org, dewittj@chromium.org
TEST=manually

Review URL: https://codereview.chromium.org/110583004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241709 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241709