chrome/browser/extensions currently use about 40 CPU minutes to compile, making it 5-10% of the total jumbo compile time when compiling chrome+blink_tests+content_shell (the reference compilation).
Supporting jumbo in chrome/browser/extensions can cut that down to 14 CPU minutes (quick and dirty hack) and maybe even less.
Comment 1 by brat...@opera.com
, Jun 7 2018