Mark some functions that wait on other processes as unsafe for IO/UI.
Mark some functions that wait on other processes as unsafe for IO/UI.

This might have helped catch an earlier bug, where we were shelling out to
lsb_release on Linux.

BUG=21782

Review URL: http://codereview.chromium.org/4149006

git-svn-id: http://src.chromium.org/svn/trunk/src@68258 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 2caa635b84133edf7bd10063517d5dff1e09633a
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser