Some content settings can't ever take effect, for example because they were set for an HTTP domain for a content type that only supports HTTPS (e.g. geolocation).
Others can't take effect temporarily, due to being overriden by a higher priority source. (e.g. user < extension < policy)
Visualize this in chrome://settings/content.
Comment 1 by msramek@chromium.org
, Aug 17