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_->IsClosable();
}
void Window::SetAlwaysOnTop(bool top) {
  window_->SetAlwaysOnTop(top);
}
bool Window::IsAlwaysOnTop() {
  return window_->IsAlwaysOnTop();
}
void Window::Center() {
  window_->Center();
}
void Window::SetPosition(int x, int y, mate::Arguments* args) {
  bool animate = false;
  args->GetNext(&animate);
  window_->SetPosition(gfx::Point(x, y), animate);
}
std::vector<int> Window::GetPosition() {
  std::vector<int> result(2);
  gfx::Point pos = window_->GetPosition();
  result[0] = pos.x();
  result[1] = pos.y();
  return result;
}
void Window::SetTitle(const std::string& title) {
  window_->SetTitle(title);
}
std::string Window::GetTitle() {
  return window_->GetTitle();
}
void Window::FlashFrame(bool flash) {