* **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.h
}  
namespace mate {
class Dictionary;
class PersistentDictionary;
}  
namespace atom {
class AtomMenuModel;
class NativeBrowserView;
struct DraggableRegion;
#if defined(OS_MACOSX)
typedef NSView* NativeWindowHandle;
#else
typedef gfx::AcceleratedWidget NativeWindowHandle;
#endif
class NativeWindow : public base::SupportsUserData,
                     public views::WidgetDelegate {
 public:
  ~NativeWindow() override;
  
  
  static NativeWindow* Create(const mate::Dictionary& options,
                              NativeWindow* parent = nullptr);
  void InitFromOptions(const mate::Dictionary& options);
  virtual void SetContentView(views::View* view) = 0;
  virtual void Close() = 0;
  virtual void CloseImmediately() = 0;
  virtual bool IsClosed() const;
  virtual void Focus(bool focus) = 0;
  virtual bool IsFocused() = 0;
  virtual void Show() = 0;