* **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.h
void SetVisibleOnAllWorkspaces(bool visible,
                                 bool visibleOnFullScreen) override;
  bool IsVisibleOnAllWorkspaces() override;
  gfx::AcceleratedWidget GetAcceleratedWidget() const override;
  NativeWindowHandle GetNativeWindowHandle() const override;
  gfx::Rect ContentBoundsToWindowBounds(const gfx::Rect& bounds) const override;
  gfx::Rect WindowBoundsToContentBounds(const gfx::Rect& bounds) const override;
  void UpdateDraggableRegions(std::unique_ptr<SkRegion> region);
  void IncrementChildModals();
  void DecrementChildModals();
#if defined(OS_WIN)
  void SetIcon(HICON small_icon, HICON app_icon);
#elif defined(USE_X11)
  void SetIcon(const gfx::ImageSkia& icon);
#endif
  SkRegion* draggable_region() const { return draggable_region_.get(); }
#if defined(OS_WIN)
  TaskbarHost& taskbar_host() { return taskbar_host_; }
#endif
 private:
  
  void OnWidgetActivationChanged(views::Widget* widget, bool active) override;
  void OnWidgetBoundsChanged(views::Widget* widget,
                             const gfx::Rect& bounds) override;
  void OnWidgetDestroying(views::Widget* widget) override;
  
  void DeleteDelegate() override;
  views::View* GetInitiallyFocusedView() override;
  bool CanResize() const override;
  bool CanMaximize() const override;