- 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 (!embedder_)
    return nullptr;
  return embedder_->web_contents();
}
v8::Local<v8::Value> WebContents::DevToolsWebContents(v8::Isolate* isolate) {
  if (devtools_web_contents_.IsEmpty())
    return v8::Null(isolate);
  else
    return v8::Local<v8::Value>::New(isolate, devtools_web_contents_);
}
v8::Local<v8::Value> WebContents::Debugger(v8::Isolate* isolate) {
  if (debugger_.IsEmpty()) {
    auto handle = atom::api::Debugger::Create(isolate, web_contents());
    debugger_.Reset(isolate, handle.ToV8());
  }
  return v8::Local<v8::Value>::New(isolate, debugger_);
}
void WebContents::BuildPrototype(v8::Isolate* isolate,
                                 v8::Local<v8::ObjectTemplate> prototype) {
  mate::ObjectTemplateBuilder(isolate, prototype)
      .MakeDestroyable()
      .SetMethod("getId", &WebContents::GetID)
      .SetMethod("equal", &WebContents::Equal)
      .SetMethod("_loadURL", &WebContents::LoadURL)
      .SetMethod("downloadURL", &WebContents::DownloadURL)
      .SetMethod("_getURL", &WebContents::GetURL)
      .SetMethod("getTitle", &WebContents::GetTitle)
      .SetMethod("isLoading", &WebContents::IsLoading)