* Electron version: 1.4.15
* Operating system: Windows 10

### Actual behavior

Height is oversized by exactly 8px consistently (taskbar is set to small icons).

![Alt](https://raw.githubusercontent.com/adi518/electron-frameless-maximize-test/master/issue.jpg)

### How to reproduce

https://github.com/adi518/electron-frameless-maximize-test
atom/browser/native_window_views.cc
content::WebContents*,
    const content::NativeWebKeyboardEvent& event) {
  keyboard_event_handler_->HandleKeyboardEvent(event, GetFocusManager());
  if (!menu_bar_)
    return;
  
  if (menu_bar_visible_ && IsAltKey(event))
    menu_bar_->SetAcceleratorVisibility(
        event.type == blink::WebInputEvent::RawKeyDown);
  
  if (event.type == blink::WebInputEvent::RawKeyDown && !IsAltKey(event) &&
      IsAltModifier(event)) {
    if (!menu_bar_visible_ &&
        (menu_bar_->GetAcceleratorIndex(event.windowsKeyCode) != -1))
      SetMenuBarVisibility(true);
    menu_bar_->ActivateAccelerator(event.windowsKeyCode);
    return;
  }
  if (!menu_bar_autohide_)
    return;
  
  if (event.type == blink::WebInputEvent::RawKeyDown && IsAltKey(event)) {
    
    menu_bar_alt_pressed_ = true;
  } else if (event.type == blink::WebInputEvent::KeyUp && IsAltKey(event) &&
             menu_bar_alt_pressed_) {