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
#include "atom/browser/native_window_views.h"
#include <string>
#include <vector>
#include "atom/browser/ui/views/menu_bar.h"
#include "atom/browser/ui/views/menu_layout.h"
#include "atom/browser/window_list.h"
#include "atom/common/color_util.h"
#include "atom/common/draggable_region.h"
#include "atom/common/native_mate_converters/image_converter.h"
#include "atom/common/options_switches.h"
#include "base/strings/utf_string_conversions.h"
#include "brightray/browser/inspectable_web_contents.h"
#include "brightray/browser/inspectable_web_contents_view.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/native_web_keyboard_event.h"
#include "native_mate/dictionary.h"
#include "ui/aura/window_tree_host.h"
#include "ui/base/hit_test.h"
#include "ui/gfx/image/image.h"
#include "ui/views/background.h"
#include "ui/views/controls/webview/unhandled_keyboard_event_handler.h"
#include "ui/views/controls/webview/webview.h"