* 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
web_contents()->GetRenderViewHost()->GetWidget()->Focus();
}
void BrowserWindow::BlurWebView() {
  web_contents()->GetRenderViewHost()->GetWidget()->Blur();
}
bool BrowserWindow::IsWebViewFocused() {
  auto* host_view = web_contents()->GetRenderViewHost()->GetWidget()->GetView();
  return host_view && host_view->HasFocus();
}
v8::Local<v8::Value> BrowserWindow::GetWebContents(v8::Isolate* isolate) {
  if (web_contents_.IsEmpty())
    return v8::Null(isolate);
  return v8::Local<v8::Value>::New(isolate, web_contents_);
}
std::unique_ptr<SkRegion> BrowserWindow::DraggableRegionsToSkRegion(
    const std::vector<DraggableRegion>& regions) {
  auto sk_region = std::make_unique<SkRegion>();
  for (const DraggableRegion& region : regions) {
    sk_region->op(
        region.bounds.x(), region.bounds.y(), region.bounds.right(),
        region.bounds.bottom(),
        region.draggable ? SkRegion::kUnion_Op : SkRegion::kDifference_Op);
  }
  return sk_region;
}
void BrowserWindow::ScheduleUnresponsiveEvent(int ms) {