In attempting to run the following command:

out/Default/content_shell --run-layout-test --enable-logging --v=3 third_party/WebKit/LayoutTests/imported/wpt/mediacapture-streams/GUM-impossible-constraint.https.html

I discovered that this generated a *lot* of output - in fact 9 million lines of code before I got tired of wating.
Analyzing the logfile gave me the following top writers:

Linecount = 9540068
('node.cc(275)', 3836021)
('message_pipe_dispatcher.cc(144)', 1568003)
('node.cc(1081)', 1559741)
('message_pipe_dispatcher.cc(539)', 1297178)
('node.cc(431)', 1276921)
('video_track_adapter.cc(507)', 671)
('node.cc(539)', 252)

This makes it hard to run stuff that depends on seeing the output of DVLOG(3) statements.