Bug 847590 - Paris binding for BeforeUnloadEvent, r=peterv

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extra : rebase_source : d249e7a7e61c39ccba52a10234e2260b048c941d
Bug 854573 - Paris binding for CompositionEvent, r=peterv

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extra : rebase_source : 3e04e198a329649d7e1f306a31cf96485f0afc0d