Bug 1001438 - Rearrange the code in nsLayoutUtils::GetDisplayPort. r=tn
Bug 1001438 - Change layers.low-precision-resolution to be a float pref instead of a divide-by-1000 int pref. r=Cwiiis
Bug 1001438 - Remove setCriticalDisplayPortForElement and have the getter function automatically compute it. r=tn
Bug 1001438 - Switch Fennec to using margins-based displayport as well. r=Cwiiis
Bug 1001438 - Refactor the GetDisplayPortImpl code for readability. r=tn