* **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.cc
window_->SetMaximizable(maximizable);
}
bool TopLevelWindow::IsMaximizable() {
  return window_->IsMaximizable();
}
void TopLevelWindow::SetFullScreenable(bool fullscreenable) {
  window_->SetFullScreenable(fullscreenable);
}
bool TopLevelWindow::IsFullScreenable() {
  return window_->IsFullScreenable();
}
void TopLevelWindow::SetClosable(bool closable) {
  window_->SetClosable(closable);
}
bool TopLevelWindow::IsClosable() {
  return window_->IsClosable();
}
void TopLevelWindow::SetAlwaysOnTop(bool top, mate::Arguments* args) {
  std::string level = "floating";
  int relative_level = 0;
  args->GetNext(&level);
  args->GetNext(&relative_level);
  std::string error;
  window_->SetAlwaysOnTop(top, level, relative_level, &error);
  if (!error.empty())
    args->ThrowError(error);
}
bool TopLevelWindow::IsAlwaysOnTop() {