- Electron version: `0.37.4`
- Operating system: Windows

When I maximize my [frameless](https://github.com/electron/electron/blob/master/docs/api/frameless-window.md) electron window a small part of the window in an unmaximized state is visible on a secondary monitor.

**Screenshot**
![electronbug](https://cloud.githubusercontent.com/assets/6634592/14762341/8849c728-09bb-11e6-85d8-de12db3fee2d.PNG)

You can visibly see the "line between the monitors" and you can see some really strange overhanging content that is over that line.

**Steps to reproduce**  
1. Open an electron app
2. Maximize the app on your secondary display
3. Look closely for the overflow onto your primary display

This might take a few times to trigger, it appears to do it about 70% of the time :confused: 

atom/browser/native_window_views.cc
#if defined(OS_WIN)
  FlipWindowStyle(GetAcceleratedWidget(), maximizable, WS_MAXIMIZEBOX);
#endif
  maximizable_ = maximizable;
}
bool NativeWindowViews::IsMaximizable() {
#if defined(OS_WIN)
  return ::GetWindowLong(GetAcceleratedWidget(), GWL_STYLE) & WS_MAXIMIZEBOX;
#else
  return true;  
#endif
}
void NativeWindowViews::SetFullScreenable(bool fullscreenable) {
  fullscreenable_ = fullscreenable;
}
bool NativeWindowViews::IsFullScreenable() {
  return fullscreenable_;
}
void NativeWindowViews::SetClosable(bool closable) {
#if defined(OS_WIN)
  HMENU menu = GetSystemMenu(GetAcceleratedWidget(), false);
  if (closable) {
    EnableMenuItem(menu, SC_CLOSE, MF_BYCOMMAND | MF_ENABLED);
  } else {
    EnableMenuItem(menu, SC_CLOSE, MF_BYCOMMAND | MF_DISABLED | MF_GRAYED);
  }
#endif
}
bool NativeWindowViews::IsClosable() {