from config.h of Android 2.2.
commit 68698168e7547cc10660828f1fb82be7a8efa845
Author: Steve Block
Date: Wed Mar 17 14:37:19 2010 +0000
Disable workers
This is because V8 on Android does not have the required locking.
Also disables channel messaging, which is used only with workers.
Bug: 2522239
Change-Id: I6cb91b4048c7e1a0351e422561625397a2e98986
via http://code.google.com/p/android/issues/detail?id=10004#c7