Revert r174254 "DevTools: Move HelpScreenUntilReload.js from "components" into "main""

DevTools won't show up.

TBR=apavlov
NOTRY=true

Review URL: https://codereview.chromium.org/282093013

git-svn-id: svn://svn.chromium.org/blink/trunk@174276 bbb929c8-8fbe-4397-9dbb-9b2b20218538