As per recent CSSWG discussion[1], >- Apple is considering changing webkit's behavior to align with the spec and other implementations, >and make page zoom affect resolution. If they decide against in, they should file a bug against the spec. > >- If Apple changes their implementation of resolution as discussed in the previous point, they are >unsure whether to keep -webkit-device-pixel-ratio a strict alias of resolution, or have it preserve >the historical behavior, but lean towards the later one. If they decide that these should not be >strict aliases, they should file a bug against the spec, which defines them to be. Since we now alias -moz-device-pixel-ratio as -webkit-device-pixel-ratio (as of v45 for the WhatWG Compatibility Standard), we should ensure that it matches whatever behavior WebKit goes with. [1] https://github.com/w3c/csswg-drafts/issues/417