Revert "Merge pull request #8941 from borjasalguero/bug_thread_id_rebased"

This reverts commit 86a79ba3fdfb0eb6f593e34887fa89e3553d1a66, reversing
changes made to a268ae3521516a8992fcaf17402ef2cac5ea2bd7 because Bug 850127 got
backed out of the b2g18 branch.