DevTools: CodeMirror.refresh is not called on wasShown anymore if the editor was already loaded.

R=pfeldman, lushnikov

Review URL: https://codereview.chromium.org/160003006

git-svn-id: svn://svn.chromium.org/blink/trunk@167025 bbb929c8-8fbe-4397-9dbb-9b2b20218538