* [x] I have read the [Contributing Guidelines](https://github.com/electron/electron/blob/master/CONTRIBUTING.md) for this project.
* [x] I agree to follow the [Code of Conduct](https://github.com/electron/electron/blob/master/CODE_OF_CONDUCT.md) that this project adheres to.
* [x] I have searched the issue tracker for an issue that matches the one I want to file, without success.

### Issue Details

* **Electron Version:** 6.0.0-beta.13
* **Operating System:** Windows 10

### Expected Behavior

When calling `browserWindow.setAlwaysOnTop(true)`, I expect the `always-on-top-changed` event to be called with the boolean `isAlwaysOnTop` parameter set to `true`, and vice versa.

### Actual Behavior

I experience the opposite of above: When calling `browserWindow.setAlwaysOnTop(true)`, my `always-on-top-changed` handler is called with `false`, and vice versa.

### To Reproduce

I don't have any JS code to share and I'm not a JS dev (I use F# and compile to JS with Fable). I think the issue should be easy to reproduce though.
shell/browser/native_window_views.cc
#if defined(OS_WIN)
  return minimizable_;
#elif defined(USE_X11)
  return true;
#endif
}
base::string16 NativeWindowViews::GetWindowTitle() const {
  return base::UTF8ToUTF16(title_);
}
views::View* NativeWindowViews::GetContentsView() {
  return root_view_.get();
}
bool NativeWindowViews::ShouldDescendIntoChildForEventHandling(
    gfx::NativeView child,
    const gfx::Point& location) {
  
  if (draggable_region() &&
      draggable_region()->contains(location.x(), location.y()))
    return false;
  
  if (!has_frame() && CanResize()) {
    FramelessView* frame =
        static_cast<FramelessView*>(widget()->non_client_view()->frame_view());
    return frame->ResizingBorderHitTest(location) == HTNOWHERE;
  }
  return true;
}
views::ClientView* NativeWindowViews::CreateClientView(views::Widget* widget) {