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
window_->SetAutoHideMenuBar(auto_hide);
}
bool Window::IsMenuBarAutoHide() {
  return window_->IsMenuBarAutoHide();
}
void Window::SetMenuBarVisibility(bool visible) {
  window_->SetMenuBarVisibility(visible);
}
bool Window::IsMenuBarVisible() {
  return window_->IsMenuBarVisible();
}
#if defined(OS_WIN)
bool Window::HookWindowMessage(UINT message,
                               const MessageCallback& callback) {
  messages_callback_map_[message] = callback;
  return true;
}
void Window::UnhookWindowMessage(UINT message) {