Standardized CSS zoom

[yotam-hacohen]

Standardized CSS zoom

Request for Mozilla Position on an Emerging Web Specification

• Specification title: Standardized CSS zoom
• Specification or proposal URL (if available): mhttps://github.com/[css-viewport] [cssom-view-1] Add a definition of the zoom CSS property w3c/csswg-drafts#9699
• Explainer URL (if available):
• Proposal author(s) (@-mention GitHub accounts): @chrishtr @yotam-hacohen

This Aligns the existing implementation of the previously non-standard CSS zoom property to align with the new standard. This changes various JS APIs to align with the spec (see design doc), change zoom to apply to iframes, and change it to apply to all inherit length properties (currently it only changes inherited font-size)

[zcorpan]

@emilio and I have reviewed the spec PR. For Gecko, it should be a net web compat win to support zoom. It also enables some use cases that are hard to impossible without zoom, such as zooming of HTML emails with text reflow in a web-based email client.

I believe @emilio 's previous concerns with interaction of some CSSOM View APIs are addressed in the new spec.

Suggest positive.