[DevTools] Clear networkConditions setting for all users because of behavior change.
[DevTools] Clear networkConditions setting for all users because of behavior change.

BUG=504444

Review URL: https://codereview.chromium.org/1218453002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@197918 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk