We occasionally use the term chrome to refer to the representation through which the user interacts with the user agent itself, as distinct from the accessed web content. This includes both primary and secondary user interface.
[3] Add non-normative description of 'browser chrome' (vkatsikaros著, ) <https://github.com/w3c/webdriver/commit/273ab5d835477a417f905d9b04521f2780ca6441>
[4] terminology: improve browser chrome definition (@ltetzlaff著, ) <https://github.com/w3c/webdriver/commit/1266ab37f6f869464dbaca256835e46a1be2fe73>