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
return window_->GetBounds();
}
void Window::SetSize(int width, int height, mate::Arguments* args) {
  bool animate = false;
  args->GetNext(&animate);
  window_->SetSize(gfx::Size(width, height), animate);
}
std::vector<int> Window::GetSize() {
  std::vector<int> result(2);
  gfx::Size size = window_->GetSize();
  result[0] = size.width();
  result[1] = size.height();
  return result;
}
void Window::SetContentSize(int width, int height, mate::Arguments* args) {
  bool animate = false;
  args->GetNext(&animate);
  window_->SetContentSize(gfx::Size(width, height), animate);
}
std::vector<int> Window::GetContentSize() {
  std::vector<int> result(2);
  gfx::Size size = window_->GetContentSize();
  result[0] = size.width();
  result[1] = size.height();
  return result;
}
void Window::SetMinimumSize(int width, int height) {