DevTools: [Regression] Callstack frames do not have stripes anymore.

BUG=404091
NOTRY=true

Review URL: https://codereview.chromium.org/468223005

git-svn-id: svn://svn.chromium.org/blink/trunk@180345 bbb929c8-8fbe-4397-9dbb-9b2b20218538