Bug 1057135 - Use MOZ_ASSERT. r=ehsan

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extra : amend_source : d6317642ffd394b129857372826edf09783d09b7
extra : transplant_source : o%1E%D7n%C9%BAe%FD%81%E1%9F%03%7D%8F%5El7%A1O%D7