Add flag to enable immersive fullscreen for v2 apps

chrome/browser/ui/gtk/apps/native_app_window_gtk.cc

Index: chrome/browser/ui/gtk/apps/native_app_window_gtk.cc
diff --git a/chrome/browser/ui/gtk/apps/native_app_window_gtk.cc b/chrome/browser/ui/gtk/apps/native_app_window_gtk.cc
index 56d4f5f3966c75251225e808c66cc0deb7ce9161..857d4343489a420380d866eae045b3acb68ce72e 100644
--- a/chrome/browser/ui/gtk/apps/native_app_window_gtk.cc
+++ b/chrome/browser/ui/gtk/apps/native_app_window_gtk.cc
@@ -593,9 +593,10 @@ gboolean NativeAppWindowGtk::OnButtonPress(GtkWidget* widget,
 
 // NativeAppWindow implementation:
 
-void NativeAppWindowGtk::SetFullscreen(bool fullscreen) {
+void NativeAppWindowGtk::SetFullscreen(int fullscreen_types) {
+  bool fullscreen = (fullscreen_types != ShellWindow::FULLSCREEN_TYPE_NONE);
   content_thinks_its_fullscreen_ = fullscreen;
-  if (fullscreen){
+  if (fullscreen) {
     if (resizable_) {
       gtk_window_fullscreen(window_);
     } else {