GetCurrentThreadId doesn't compile on android

Also reverts follow up build fix attempts

BUG=none
LOG=n
TBR=jarin@chromium.org

Review URL: https://codereview.chromium.org/337093005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22104 ce2b1a6d-e550-0410-aec6-3dcde31c8c00