- 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
const int kMenuBarHeight = 20;
#else
const int kMenuBarHeight = 25;
#endif
#if defined(OS_WIN)
gfx::Rect SubtractBorderSize(gfx::Rect bounds) {
  gfx::Point borderSize = gfx::Point(
      GetSystemMetrics(SM_CXSIZEFRAME) - 1,   
      GetSystemMetrics(SM_CYSIZEFRAME) - 1);  
  gfx::Point dpiAdjustedSize =
      display::win::ScreenWin::ScreenToDIPPoint(borderSize);
  bounds.set_x(bounds.x() + dpiAdjustedSize.x());
  bounds.set_y(bounds.y() + dpiAdjustedSize.y());
  bounds.set_width(bounds.width() - 2 * dpiAdjustedSize.x());
  bounds.set_height(bounds.height() - 2 * dpiAdjustedSize.y());
  return bounds;
}
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) {