Bug 984196 - glxtest should use _exit instead of exit. r=bgirard

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extra : rebase_source : 3bba6badd7e5a4031ad402cf88f7e0a15f4ba386
Bug 963158 - Profiler shouldn't sample sleeping threads multiple times. r=bgirard,roc,bent,froydnj

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extra : rebase_source : 75789c4359a2cb02b2588cfbc9b6b3cbd1e79c78