VR: Disable select element in VR mode via WebPreferences

third_party/WebKit/Source/core/html/HTMLSelectElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights
  * reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
@@ skipping 1931 matching lines @@
   if (GetDocument().GetPage()->GetChromeClient().HasOpenedPopup())
     return;
   if (!GetLayoutObject() || !GetLayoutObject()->IsMenuList())
     return;
   if (VisibleBoundsInVisualViewport().IsEmpty())
     return;
 
   if (!popup_)
     popup_ = GetDocument().GetPage()->GetChromeClient().OpenPopupMenu(
         *GetDocument().GetFrame(), *this);
+  if (!popup_)
+    return;
+
   popup_is_visible_ = true;
   ObserveTreeMutation();
 
   LayoutMenuList* menu_list = ToLayoutMenuList(GetLayoutObject());
   popup_->Show();
   if (AXObjectCache* cache = GetDocument().ExistingAXObjectCache())
     cache->DidShowMenuListPopup(menu_list);
 }
 
 void HTMLSelectElement::HidePopup() {
@@ skipping 97 matching lines @@
   popup_updater_ = nullptr;
 }
 
 void HTMLSelectElement::DidMutateSubtree() {
   DCHECK(PopupIsVisible());
   DCHECK(popup_);
   popup_->UpdateFromElement(PopupMenu::kByDOMChange);
 }
 
 }  // namespace blink