Fixed notify functions behavior.

git-svn-id: http://svn.boost.org/svn/boost/trunk@86546 b8fc166d-592f-0410-95f2-cb63ce0dd405
Chrono: apply patch for #9337.

git-svn-id: http://svn.boost.org/svn/boost/trunk@86547 b8fc166d-592f-0410-95f2-cb63ce0dd405