Created attachment 8492178 [details] debug_browser_console.png Win32 mozilla-central-debug of 2014-09-18 See attached image. The console within the Web Console has a commandline.
It's disabled by default until the pref "devtools.chrome.enabled" is true for security purposes. There's also a toggle in the toolbox settings (gear icon) that says "Enable chrome and add-on debugging". Please reopen if this does not resolve the issue.