* **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
virtual extensions::SizeConstraints GetContentSizeConstraints() const;
  virtual void SetMinimumSize(const gfx::Size& size);
  virtual gfx::Size GetMinimumSize() const;
  virtual void SetMaximumSize(const gfx::Size& size);
  virtual gfx::Size GetMaximumSize() const;
  virtual gfx::Size GetContentMinimumSize() const;
  virtual gfx::Size GetContentMaximumSize() const;
  virtual void SetSheetOffset(const double offsetX, const double offsetY);
  virtual double GetSheetOffsetX();
  virtual double GetSheetOffsetY();
  virtual void SetResizable(bool resizable) = 0;
  virtual void MoveTop() = 0;
  virtual bool IsResizable() = 0;
  virtual void SetMovable(bool movable) = 0;
  virtual bool IsMovable() = 0;
  virtual void SetMinimizable(bool minimizable) = 0;
  virtual bool IsMinimizable() = 0;
  virtual void SetMaximizable(bool maximizable) = 0;
  virtual bool IsMaximizable() = 0;
  virtual void SetFullScreenable(bool fullscreenable) = 0;
  virtual bool IsFullScreenable() = 0;
  virtual void SetClosable(bool closable) = 0;
  virtual bool IsClosable() = 0;
  virtual void SetAlwaysOnTop(bool top,
                              const std::string& level = "floating",
                              int relativeLevel = 0,
                              std::string* error = nullptr) = 0;
  virtual bool IsAlwaysOnTop() = 0;
  virtual void Center() = 0;
  virtual void Invalidate() = 0;