* 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
namespace {
#if defined(OS_WIN)
const int kMenuBarHeight = 20;
#else
const int kMenuBarHeight = 25;
#endif
#if defined(OS_WIN)
void FlipWindowStyle(HWND handle, bool on, DWORD flag) {
  DWORD style = ::GetWindowLong(handle, GWL_STYLE);
  if (on)
    style |= flag;
  else
    style &= ~flag;
  ::SetWindowLong(handle, GWL_STYLE, style);
}
#endif
bool IsAltKey(const content::NativeWebKeyboardEvent& event) {
  return event.windowsKeyCode == ui::VKEY_MENU;
}
bool IsAltModifier(const content::NativeWebKeyboardEvent& event) {
  typedef content::NativeWebKeyboardEvent::Modifiers Modifiers;
  int modifiers = event.modifiers;
  modifiers &= ~Modifiers::NumLockOn;
  modifiers &= ~Modifiers::CapsLockOn;
  return (modifiers == Modifiers::AltKey) ||
         (modifiers == (Modifiers::AltKey | Modifiers::IsLeft)) ||
         (modifiers == (Modifiers::AltKey | Modifiers::IsRight));
}
#if defined(USE_X11)
int SendClientEvent(XDisplay* display, ::Window window, const char* msg) {