Bug 1062256 - Followup to disable »What is this« bubble for 33-specific code paths [r=ttaubert a=sylvestre]
Short circuit intro initialization so no text is shown.
Bug 1073823 - Turn off enhanced tiles for all Firefox 33 users [r=ttaubert a=sylvestre]
Check for a _testing value that only gets set for the xpcshell test. Override enabled for mochitest.