DevTools: [Styles] Remove the color format selector Cog menu

R=aandrey, eustas, vsevik
BUG=333840

Review URL: https://codereview.chromium.org/136613004

git-svn-id: svn://svn.chromium.org/blink/trunk@164983 bbb929c8-8fbe-4397-9dbb-9b2b20218538