* 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
window_->CenterWindow(GetSize());
}
void NativeWindowViews::Invalidate() {
  window_->SchedulePaintInRect(gfx::Rect(GetBounds().size()));
}
void NativeWindowViews::SetTitle(const std::string& title) {
  title_ = title;
  window_->UpdateWindowTitle();
}
std::string NativeWindowViews::GetTitle() {
  return title_;
}
void NativeWindowViews::FlashFrame(bool flash) {
#if defined(OS_WIN)
  
  if (!flash) {
    FLASHWINFO fwi;
    fwi.cbSize = sizeof(fwi);
    fwi.hwnd = GetAcceleratedWidget();
    fwi.dwFlags = FLASHW_STOP;
    fwi.uCount = 0;
    FlashWindowEx(&fwi);
    return;
  }
#endif
  window_->FlashFrame(flash);
}
void NativeWindowViews::SetSkipTaskbar(bool skip) {