Use correct cascading order for Shadow DOM v1

third_party/WebKit/Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1934 matching lines @@
     if (!tagNameIsSupported) {
         exceptionState.throwDOMException(NotSupportedError, "This element does not support attachShadow");
         return nullptr;
     }
 
     if (shadowRootInitDict.hasMode() && shadowRoot()) {
         exceptionState.throwDOMException(InvalidStateError, "Shadow root cannot be created on a host which already hosts a shadow tree.");
         return nullptr;
     }
 
+    document().styleEngine().setUseCascadeOrderForShadowDOMV1();
+
     ShadowRootType type = ShadowRootType::V0;
     if (shadowRootInitDict.hasMode())
         type = shadowRootInitDict.mode() == "open" ? ShadowRootType::Open : ShadowRootType::Closed;
 
     if (type == ShadowRootType::Closed)
         UseCounter::count(document(), UseCounter::ElementAttachShadowClosed);
     else if (type == ShadowRootType::Open)
         UseCounter::count(document(), UseCounter::ElementAttachShadowOpen);
 
     RefPtrWillBeRawPtr<ShadowRoot> shadowRoot = createShadowRootInternal(type, exceptionState);
@@ skipping 1705 matching lines @@
 {
 #if ENABLE(OILPAN)
     if (hasRareData())
         visitor->trace(elementRareData());
     visitor->trace(m_elementData);
 #endif
     ContainerNode::trace(visitor);
 }
 
 } // namespace blink