* **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/api/atom_api_top_level_window.h
bool* prevent_default) override;
  void OnWindowMove() override;
  void OnWindowMoved() override;
  void OnWindowScrollTouchBegin() override;
  void OnWindowScrollTouchEnd() override;
  void OnWindowSwipe(const std::string& direction) override;
  void OnWindowSheetBegin() override;
  void OnWindowSheetEnd() override;
  void OnWindowEnterFullScreen() override;
  void OnWindowLeaveFullScreen() override;
  void OnWindowEnterHtmlFullScreen() override;
  void OnWindowLeaveHtmlFullScreen() override;
  void OnWindowAlwaysOnTopChanged() override;
  void OnExecuteAppCommand(const std::string& command_name) override;
  void OnTouchBarItemResult(const std::string& item_id,
                            const base::DictionaryValue& details) override;
  void OnNewWindowForTab() override;
#if defined(OS_WIN)
  void OnWindowMessage(UINT message, WPARAM w_param, LPARAM l_param) override;
#endif
  
  void SetContentView(mate::Handle<View> view);
  void Close();
  virtual void Focus();
  virtual void Blur();
  bool IsFocused();
  void Show();
  void ShowInactive();
  void Hide();
  bool IsVisible();