- Electron version: v0.37.5
- Operating system: Any

It would be useful if we can open DevTools choosing all of it's available position: detached, docked right or docked bottom.

The new API could be something like this:
# webContents.openDevTools([options])

Opens the devtools.
- options Object (optional)
  - mode String - ['detached' | 'right' | 'bottom'] . opens DevTools in specified position. Defaults to last used mode.
  - detach Boolean - opens DevTools in a new window (deprecated, use mode: 'detached')

atom/browser/api/atom_api_web_contents.cc
if (type_ == REMOTE)
    return;
  managed_web_contents()->CloseDevTools();
}
bool WebContents::IsDevToolsOpened() {
  if (type_ == REMOTE)
    return false;
  return managed_web_contents()->IsDevToolsViewShowing();
}
bool WebContents::IsDevToolsFocused() {
  if (type_ == REMOTE)
    return false;
  return managed_web_contents()->GetView()->IsDevToolsViewFocused();
}
void WebContents::EnableDeviceEmulation(
    const blink::WebDeviceEmulationParams& params) {
  if (type_ == REMOTE)
    return;
  Send(new ViewMsg_EnableDeviceEmulation(routing_id(), params));
}
void WebContents::DisableDeviceEmulation() {
  if (type_ == REMOTE)
    return;
  Send(new ViewMsg_DisableDeviceEmulation(routing_id()));
}
void WebContents::ToggleDevTools() {