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
window_->Maximize();
}
void Window::Unmaximize() {
  window_->Unmaximize();
}
bool Window::IsMaximized() {
  return window_->IsMaximized();
}
void Window::Minimize() {
  window_->Minimize();
}
void Window::Restore() {
  window_->Restore();
}
bool Window::IsMinimized() {
  return window_->IsMinimized();
}
void Window::SetFullScreen(bool fullscreen) {
  window_->SetFullScreen(fullscreen);
}
bool Window::IsFullscreen() {
  return window_->IsFullscreen();
}
void Window::SetBounds(const gfx::Rect& bounds, mate::Arguments* args) {
  bool animate = false;
  args->GetNext(&animate);
  window_->SetBounds(bounds, animate);
}
gfx::Rect Window::GetBounds() {