We can get the content size and the window size, but not the chrome position.

At the moment we do this:

```
leftBorderWidth = (windowWidth - contentWidth) / 2;
titlebarHeight = windowHeight - (contentHeight + leftBorderWidth);
```

which makes some assumptions so therefore feels a bit wrong.

it would be nice if alongside getContentSize (https://github.com/electron/electron/blob/master/docs/api/browser-window.md#wingetcontentsize) there was a getContentOffset.

I've been looking at the C++ - https://github.com/electron/electron/blob/e05804848f98959d63337aacd9047cd579c5b23f/chromium_src/extensions/browser/app_window/size_constraints.cc and I don't see an easy way to get this information - do you have any ideas or pointers if you accept this as a feature request?

atom/browser/api/atom_api_window.cc
Emit("responsive");
}
void Window::OnExecuteWindowsCommand(const std::string& command_name) {
  Emit("app-command", command_name);
}
#if defined(OS_WIN)
void Window::OnWindowMessage(UINT message, WPARAM w_param, LPARAM l_param) {
  if (IsWindowMessageHooked(message)) {
    messages_callback_map_[message].Run(
        ToBuffer(isolate(), static_cast<void*>(&w_param), sizeof(WPARAM)),
        ToBuffer(isolate(), static_cast<void*>(&l_param), sizeof(LPARAM)));
  }
}
#endif
mate::WrappableBase* Window::New(mate::Arguments* args) {
  if (!Browser::Get()->is_ready()) {
    args->ThrowError("Cannot create BrowserWindow before app is ready");
    return nullptr;
  }
  if (args->Length() > 1) {
    args->ThrowError();
    return nullptr;
  }
  mate::Dictionary options;
  if (!(args->Length() == 1 && args->GetNext(&options))) {
    options = mate::Dictionary::CreateEmpty(args->isolate());
  }
  return new Window(args->isolate(), args->GetThis(), options);
}
void Window::Close() {