Implement ShadowRoot.delegatesFocus 1/4 (focus navigation)

Source/core/dom/shadow/ShadowRoot.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Neither the name of Google Inc. nor the names of its
@@ skipping 44 matching lines @@
 
 ShadowRoot::ShadowRoot(Document& document, ShadowRootType type)
     : DocumentFragment(0, CreateShadowRoot)
     , TreeScope(*this, document)
     , m_prev(nullptr)
     , m_next(nullptr)
     , m_numberOfStyles(0)
     , m_type(type)
     , m_registeredWithParentShadowRoot(false)
     , m_descendantInsertionPointsIsValid(false)
+    , m_delegatesFocus(false)
 {
 }
 
 ShadowRoot::~ShadowRoot()
 {
 #if !ENABLE(OILPAN)
     ASSERT(!m_prev);
     ASSERT(!m_next);
 
     if (m_shadowRootRareData && m_shadowRootRareData->styleSheets())
@@ skipping 250 matching lines @@
 DEFINE_TRACE(ShadowRoot)
 {
     visitor->trace(m_prev);
     visitor->trace(m_next);
     visitor->trace(m_shadowRootRareData);
     TreeScope::trace(visitor);
     DocumentFragment::trace(visitor);
 }
 
 }