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/native_window_views.cc
NotifyWindowMove();
}
gfx::Size NativeWindowViews::ContentSizeToWindowSize(const gfx::Size& size) {
  if (!has_frame())
    return size;
  gfx::Size window_size(size);
#if defined(OS_WIN)
  HWND hwnd = GetAcceleratedWidget();
  gfx::Rect dpi_bounds = gfx::Rect(
      gfx::Point(), display::win::ScreenWin::DIPToScreenSize(hwnd, size));
  gfx::Rect window_bounds = display::win::ScreenWin::ScreenToDIPRect(
      hwnd,
      window_->non_client_view()->GetWindowBoundsForClientBounds(dpi_bounds));
  window_size = window_bounds.size();
#endif
  if (menu_bar_ && menu_bar_visible_)
    window_size.set_height(window_size.height() + kMenuBarHeight);
  return window_size;
}
gfx::Size NativeWindowViews::WindowSizeToContentSize(const gfx::Size& size) {