- 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
views::Widget* widget, bool active) {
  if (widget != window_.get())
    return;
  
  content::BrowserThread::PostTask(
      content::BrowserThread::UI, FROM_HERE,
      base::Bind(active ? &NativeWindow::NotifyWindowFocus :
                          &NativeWindow::NotifyWindowBlur,
                 GetWeakPtr()));
  if (active && inspectable_web_contents() &&
      !inspectable_web_contents()->IsDevToolsViewShowing())
    web_contents()->Focus();
  
  if (!active && menu_bar_autohide_ && menu_bar_visible_)
    SetMenuBarVisibility(false);
}
void NativeWindowViews::OnWidgetBoundsChanged(
    views::Widget* widget, const gfx::Rect& bounds) {
  if (widget != window_.get())
    return;
  if (widget_size_ != bounds.size()) {
    NotifyWindowResize();
    widget_size_ = bounds.size();
  }
}
void NativeWindowViews::DeleteDelegate() {