Allow to set and remember zoom level across pages for scheme and host combination as in browsers

WIth firefox and chromium when user zooms a page, browser actually remembers set zoom level for scheme/host pair - basically for a whole web site, and not just a one single tab. Newly opened tab with the same url (and probably different path piece) will get set zoom and not default one. It would be useful to allow such a usecase. This is possible with public content api, although two problems should be solved somehow:

• how it would interact with existing setZoomLevel api in page/view, and what would take precedence (it should probably be always possible to always override zoom set for url - then it would be compatible with existing methods)
• how to store this settings so that they survive across restarts for convenience.