Bug 914762 - Allow nsThread to be subclassed, r=bsmedberg.

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extra : transplant_source : %BD%C5%CB%7Fx%82q%FC%B6%AA%8B%8E%9Fo%BE%82%DE%09h%FF
Bug 914762 - Switch Workers to use a normal nsThread event loop, r=mrbkap.

--HG--
extra : transplant_source : /%93%60%CC%3A%16%B16%A1%5Bmx%9F%FA%7B%10JD%F0%E7