Pass the SIGPROF signal on to previously registered signal handler.
Pass the SIGPROF signal on to previously registered signal handler.

This enables the google-perftools SIGPROF signal handler to continue to work properly.

BUG=none

Review URL: https://codereview.chromium.org/11195045
Patch from William Chan <willchan@chromium.org>.

git-svn-id: b158db1e4b4ab85d4c9e510fdef4b1e8c614b15b@12889 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh