* Electron Version: 3.0.0-beta1
* Operating System (Platform and Version): macOS
* Last known working Electron version: 2.0.2

**Expected Behavior**
```css
html, body, * {
    -webkit-app-region: drag;
    -webkit-user-select: none;
    cursor: default;
}
```
should allow users to move the position of the window by dragging it directly.

**Actual behavior**
The window is not draggable.
The `cursor` and `-webkit-user-select` properties work well.

**To Reproduce**
copy the CSS above, paste it into a frameless app's `<style>` tag, and run the app.

**Screenshots**

**Additional Information**

atom/browser/api/atom_api_browser_window.cc
api_web_contents_->RemoveObserver(this);
  
  
  if (web_contents())
    Cleanup();
}
void BrowserWindow::OnInputEvent(const blink::WebInputEvent& event) {
  switch (event.GetType()) {
    case blink::WebInputEvent::kGestureScrollBegin:
    case blink::WebInputEvent::kGestureScrollUpdate:
    case blink::WebInputEvent::kGestureScrollEnd:
      Emit("scroll-touch-edge");
      break;
    default:
      break;
  }
}
void BrowserWindow::RenderViewHostChanged(content::RenderViewHost* old_host,
                                          content::RenderViewHost* new_host) {
  if (old_host)
    old_host->GetWidget()->RemoveInputEventObserver(this);
  if (new_host)
    new_host->GetWidget()->AddInputEventObserver(this);
}
void BrowserWindow::RenderViewCreated(