Internally, replace the watchlist array with a hashmap since the array
assumes properties are enumerated in a consistent order and foreach()
probably won't. (find_nth() never guaranteed this either but it usually
worked in practice.)
Signed-off-by: Greg Hackmann <ghackmann@google.com>
(cherry picked from commit 389e358017)
Change-Id: I1db3137b130474f4bb205f01f0bdcf37cf974764
Greg Hackmann