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
if (is_modal())
      state_atom_list.push_back(GetAtom("_NET_WM_STATE_MODAL"));
  }
  ui::SetAtomArrayProperty(GetAcceleratedWidget(), "_NET_WM_STATE", "ATOM",
                           state_atom_list);
  
  if (!window_type.empty())
    SetWindowType(GetAcceleratedWidget(), window_type);
#endif
  
  SetLayoutManager(new MenuLayout(this, kMenuBarHeight));
  AddChildView(web_view_);
#if defined(OS_WIN)
  if (!has_frame()) {
    
    
    DWORD frame_style = WS_CAPTION;
    if (resizable_)
      frame_style |= WS_THICKFRAME;
    if (minimizable_)
      frame_style |= WS_MINIMIZEBOX;
    if (maximizable_)
      frame_style |= WS_MAXIMIZEBOX;
    
    if (!thick_frame_)
      frame_style &= ~(WS_THICKFRAME | WS_CAPTION);
    ::SetWindowLong(GetAcceleratedWidget(), GWL_STYLE, frame_style);
  }
  LONG ex_style = ::GetWindowLong(GetAcceleratedWidget(), GWL_EXSTYLE);