Bug 982141 - Expose the logic used to decide whether a scrollable frame should be async scrollable. r=tn

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extra : rebase_source : 1e1c2c9377b7127683fe555450fcf2354934fe93
Bug 982141 - Move CalculateRootCompositionSize to nsLayoutUtils and clean it up a bit. r=tn

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extra : rebase_source : 8ffa71055b05836ce166b6b2c8c9896b6d08fdd5
Bug 982141 - Calculate frame metrics for a display port calculation. r=kats,tn

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extra : rebase_source : 23ac67b5f528726869f5fd3565afa957347b336d
Bug 982141 - Factor out 'wantSubAPZC' into nsLayoutUtils. r=kats,tn

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extra : rebase_source : d651c8b224c31518816a29afc003ef5ac6ed7cc7
Bug 982141 - Introduce nsLayoutUtils::SetDisplayPortMargins, with an option to not repaint. r=tn

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extra : rebase_source : 7d8245831828d60df4fb6e20d98fd2b08d4e3857
Bug 982141 - Make sure the primary async-scrollable frame has a displayport set. r=tn

--HG--
extra : rebase_source : cecfe35b5407d6bbe1709eb0a2abf55ab8503c2d