- 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
return web_contents()->IsWaitingForResponse();
}
void WebContents::Stop() {
  web_contents()->Stop();
}
void WebContents::GoBack() {
  atom::AtomBrowserClient::SuppressRendererProcessRestartForOnce();
  web_contents()->GetController().GoBack();
}
void WebContents::GoForward() {
  atom::AtomBrowserClient::SuppressRendererProcessRestartForOnce();
  web_contents()->GetController().GoForward();
}
void WebContents::GoToOffset(int offset) {
  atom::AtomBrowserClient::SuppressRendererProcessRestartForOnce();
  web_contents()->GetController().GoToOffset(offset);
}
bool WebContents::IsCrashed() const {
  return web_contents()->IsCrashed();
}
void WebContents::SetUserAgent(const std::string& user_agent) {
  web_contents()->SetUserAgentOverride(user_agent);
  scoped_refptr<net::URLRequestContextGetter> getter =
      web_contents()->GetBrowserContext()->GetRequestContext();
  auto accept_lang = l10n_util::GetApplicationLocale("");
  getter->GetNetworkTaskRunner()->PostTask(FROM_HERE,
      base::Bind(&SetUserAgentInIO, getter, accept_lang, user_agent));
}
std::string WebContents::GetUserAgent() {