* **Electron Version:**
  4.0.2
* **Operating System:**
  macOS 10.14.3
* **Last Known Working Electron version:**:
  1.7

### Expected Behavior
When creating a BrowserWindow it should not appear in the dock menu by defaults.

### Actual Behavior
It appears in the dock menu (example: `raven` in https://electronjs.org/docs/tutorial/macos-dock)

### To Reproduce
Just create new BrowserWindow, then right click on the app icon in the dock. (see https://electronjs.org/docs/tutorial/macos-dock)

At least it should be a way to control that, this can be achieve for top level window with:
`[window_ setExcludedFromWindowsMenu:YES];`, indeed [window isExcludedFromWindowsMenu] returns false by default, see

https://developer.apple.com/documentation/appkit/nsapplication/1428625-removewindowsitem
`Use the isExcludedFromWindowsMenu method of NSWindow if you want the item to remain excluded from the Window menu.`
https://developer.apple.com/documentation/appkit/nswindow/1419175-isexcludedfromwindowsmenu

atom/browser/native_window_views.cc
::GetWindowPlacement(GetAcceleratedWidget(), &wp);
    ::ShowWindow(GetAcceleratedWidget(), SW_HIDE);
    ::ShowWindow(GetAcceleratedWidget(), wp.showCmd);
    ::BringWindowToTop(GetAcceleratedWidget());
  }
#endif
}
gfx::NativeView NativeWindowViews::GetNativeView() const {
  return widget()->GetNativeView();
}
gfx::NativeWindow NativeWindowViews::GetNativeWindow() const {
  return widget()->GetNativeWindow();
}
void NativeWindowViews::SetProgressBar(double progress,
                                       NativeWindow::ProgressState state) {
#if defined(OS_WIN)
  taskbar_host_.SetProgressBar(GetAcceleratedWidget(), progress, state);
#elif defined(USE_X11)
  if (unity::IsRunning()) {
    unity::SetProgressFraction(progress);
  }
#endif
}
void NativeWindowViews::SetOverlayIcon(const gfx::Image& overlay,
                                       const std::string& description) {
#if defined(OS_WIN)
  taskbar_host_.SetOverlayIcon(GetAcceleratedWidget(), overlay, description);
#endif
}
void NativeWindowViews::SetAutoHideMenuBar(bool auto_hide) {