DevTools: nit refactoring in ScriptsPanel.js to remove code dups.
DevTools: nit refactoring in ScriptsPanel.js to remove code dups.

BUG=None
R=vsevik@chromium.org

Review URL: https://codereview.chromium.org/18523003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@153580 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs