First point I have to make about this (and I have made it before on other food safety threads): As soon as you ask the question, "is this safe?" you MUST answer "no." If the question has come up at all, that's a good enough sign that there is a danger, and this applies to poultry as much as anything. Sure, you might throw away food that was actually untainted, but the chance that you might end up eating tainted food is not worth the risk. Remember that food poisoning is potentially fatal!
If you want a good, fast, safe method to defrost a whole chicken, try brining it. Submerge it in cold water (completely) that has had salt and sugar added to it. You will get a really moist, tasty bird, and the water will regulate the temperature on the surface of the bird and prevent it from reaching the "danger zone". And it will defrost faster than if it is exposed to the air. Defrosting is not about temperature, it is about heat transfer, and water is far more efficient at it than air is.