Bug 1058335 (part 1) - Used |mFoo| form for PLDHashTable's private members. r=roc.

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extra : rebase_source : d5aed65f2c9dcbe288062599282e71ed458872bf
Bug 1058335 (part 2) - Remove unneeded comments and always-ignored warnings about chaining. r=roc.

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extra : rebase_source : d96d6beabd48da66ae991274b66e93f5d193c61e