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.cc
CR_DEFINE_STATIC_LOCAL(const gfx::FontRenderParams, params,
      (gfx::GetFontRenderParams(gfx::FontRenderParamsQuery(), nullptr)));
  prefs->should_antialias_text = params.antialiasing;
  prefs->use_subpixel_positioning = params.subpixel_positioning;
  prefs->hinting = params.hinting;
  prefs->use_autohinter = params.autohinter;
  prefs->use_bitmaps = params.use_bitmaps;
  prefs->subpixel_rendering = params.subpixel_rendering;
#endif
  
  
  ui::GpuSwitchingManager::SetTransparent(transparent_);
  WindowList::AddWindow(this);
}
NativeWindow::~NativeWindow() {
  
  
  NotifyWindowClosed();
}
NativeWindow* NativeWindow::FromWebContents(
    content::WebContents* web_contents) {
  WindowList& window_list = *WindowList::GetInstance();
  for (NativeWindow* window : window_list) {
    if (window->web_contents() == web_contents)
      return window;
  }
  return nullptr;
}
void NativeWindow::InitFromOptions(const mate::Dictionary& options) {