* Electron version: 1.6.0, does _not_ repro in 1.4.x
* Operating system: Win32 tested, others possible

It appears that even if you create a window with `focusable: false` and `show: false`, calling `loadURL` on it will cause it to accept window focus and for other windows to lose focus.

### How to reproduce

Open the default Electron app

```js
BW = require('electron').remote.BrowserWindow
let ourWindow = BW.getFocusedWindow()
ourWindow.on('blur', () => console.log("Lost it!"))

hidden = new BW({show: false, width: 500, height: 500, focusable: false})
hidden.loadURL("http://www.yahoo.com")

>>> "Lost it!"
```

This breaks anyone using background windows for computation such as VS Code and Slack (via electron-remote), because whenever a background task kicks off, users can't type anymore
atom/browser/native_window_views.cc
menu_bar_->ActivateAccelerator(event.windowsKeyCode);
    return;
  }
  if (!menu_bar_autohide_)
    return;
  
  if (event.type == blink::WebInputEvent::RawKeyDown && IsAltKey(event)) {
    
    menu_bar_alt_pressed_ = true;
  } else if (event.type == blink::WebInputEvent::KeyUp && IsAltKey(event) &&
             menu_bar_alt_pressed_) {
    
    menu_bar_alt_pressed_ = false;
    SetMenuBarVisibility(!menu_bar_visible_);
  } else {
    
    menu_bar_alt_pressed_ = false;
  }
}
gfx::Size NativeWindowViews::GetMinimumSize() {
  return NativeWindow::GetMinimumSize();
}
gfx::Size NativeWindowViews::GetMaximumSize() {
  return NativeWindow::GetMaximumSize();
}
bool NativeWindowViews::AcceleratorPressed(const ui::Accelerator& accelerator) {
  return accelerator_util::TriggerAcceleratorTableCommand(
      &accelerator_table_, accelerator);
}
void NativeWindowViews::RegisterAccelerators(AtomMenuModel* menu_model) {