Well now that you mention //docs...
"Subtle Threading Bugs" [1] and "Threading" [2] are out-of-date too, to the point of having wrong code and outdated suggestions.
E.g.: "file_thread: A general process thread for file operations. When you want to do blocking filesystem operations (for example, requesting an icon for a file type, or writing downloaded files to disk), dispatch to this thread."
and: "You should always use BrowserThread to post tasks between threads."
So IMO, at least a large "This is out-of-date" with links to the correct documentation is called for, given how complicated the state of things already seems [3]. Bumping to Pri-2 because docs are wrong.
[1] https://cs.chromium.org/chromium/src/docs/subtle_threading_bugs.md
[2] https://chromium.googlesource.com/chromium/src/+/master/docs/design/threading.md
[3] https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/RPHKykJ4qb0 ;-)
Comment 1 by tzik@chromium.org
, Aug 4 2017