Additional cleanups for PRTimeTest.  We already have a microseconds-per-milliseconds constant, use it.  Do less per-OS #ifdeffing.
Additional cleanups for PRTimeTest.  We already have a microseconds-per-milliseconds constant, use it.  Do less per-OS #ifdeffing.

git-svn-id: http://src.chromium.org/svn/trunk/src@714 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 8e27915577fee85d11dd13586618392aa20a27b6
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