Bug 968604: Fork the browser process from Nuwa. r=khuey a=1.3t+
Bug 968604 Part 2: Test case fix: clean up the preallocated process in an async manner. r=khuey a=1.3t+
Bug 968604: Temporarily disable test case test_Preallocated.html in mochitest-2 suite before the Shutdown hang is fixed. r=fabrice a=1.3t+