Использование .pac файла для коммутации прокси-серверов

Полезная ссылка

chromium

You may enforce that all chromium browser instances on a machine use the autoconfig url. Place a file (e.g. proxyConfig) below /etc/chromium-browser/policies/managed/ with the following content

Use git through a proxy

Tutorial: how to use git through a proxy

What kind of proxy

The most common are an HTTP proxy, and a SOCKS5 proxy - for example, one opened with the ssh -D command, documented in ssh(1). 

Настройка Firefox

Масштаб по умолчанию

about:config -> layout.css.devPixelsPerPx