Only allow one shadowRoot.

sky/engine/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 23 matching lines @@
 #include "sky/engine/core/dom/StyleEngine.h"
 #include "sky/engine/core/dom/Text.h"
 #include "sky/engine/core/dom/shadow/ElementShadow.h"
 #include "sky/engine/core/dom/shadow/InsertionPoint.h"
 #include "sky/engine/core/dom/shadow/ShadowRootRareData.h"
 #include "sky/engine/core/editing/markup.h"
 #include "sky/engine/public/platform/Platform.h"
 
 namespace blink {
 
-struct SameSizeAsShadowRoot : public DocumentFragment, public TreeScope, public DoublyLinkedListNode<ShadowRoot> {
-    void* pointers[3];
+struct SameSizeAsShadowRoot : public DocumentFragment, public TreeScope {
+    void* pointers[1];
     unsigned countersAndFlags[1];
 };
 
 COMPILE_ASSERT(sizeof(ShadowRoot) == sizeof(SameSizeAsShadowRoot), shadowroot_should_stay_small);
 
 ShadowRoot::ShadowRoot(Document& document)
     : DocumentFragment(0, CreateShadowRoot)
     , TreeScope(*this, document)
-    , m_prev(nullptr)
-    , m_next(nullptr)
     , m_numberOfStyles(0)
     , m_registeredWithParentShadowRoot(false)
     , m_descendantInsertionPointsIsValid(false)
 {
 }
 
 ShadowRoot::~ShadowRoot()
 {
-#if !ENABLE(OILPAN)
-    ASSERT(!m_prev);
-    ASSERT(!m_next);
-
     if (m_shadowRootRareData && m_shadowRootRareData->styleSheets())
         m_shadowRootRareData->styleSheets()->detachFromDocument();
 
     document().styleEngine()->didRemoveShadowRoot(this);
 
     // We cannot let ContainerNode destructor call willBeDeletedFromDocument()
     // for this ShadowRoot instance because TreeScope destructor
     // clears Node::m_treeScope thus ContainerNode is no longer able
     // to access it Document reference after that.
     willBeDeletedFromDocument();
 
     // We must remove all of our children first before the TreeScope destructor
     // runs so we don't go through TreeScopeAdopter for each child with a
     // destructed tree scope in each descendant.
     removeDetachedChildren();
 
     // We must call clearRareData() here since a ShadowRoot class inherits TreeScope
     // as well as Node. See a comment on TreeScope.h for the reason.
     if (hasRareData())
         clearRareData();
-#endif
 }
 
-#if !ENABLE(OILPAN)
 void ShadowRoot::dispose()
 {
     removeDetachedChildren();
 }
-#endif
 
 PassRefPtr<Node> ShadowRoot::cloneNode(bool, ExceptionState& exceptionState)
 {
     exceptionState.throwDOMException(DataCloneError, "ShadowRoot nodes are not clonable.");
     return nullptr;
 }
 
 void ShadowRoot::recalcStyle(StyleRecalcChange change)
 {
     if (styleChangeType() >= SubtreeStyleChange)
@@ skipping 16 matching lines @@
         }
     }
 
     clearChildNeedsStyleRecalc();
 }
 
 void ShadowRoot::insertedInto(ContainerNode* insertionPoint)
 {
     DocumentFragment::insertedInto(insertionPoint);
 
-    if (!insertionPoint->inDocument() || !isOldest())
+    if (!insertionPoint->inDocument())
         return;
 
     // FIXME: When parsing <video controls>, insertedInto() is called many times without invoking removedFrom.
     // For now, we check m_registeredWithParentShadowroot. We would like to ASSERT(!m_registeredShadowRoot) here.
     // https://bugs.webkit.org/show_bug.cig?id=101316
     if (m_registeredWithParentShadowRoot)
         return;
 
     if (ShadowRoot* root = host()->containingShadowRoot()) {
         root->addChildShadowRoot();
@@ skipping 103 matching lines @@
 
 StyleSheetList* ShadowRoot::styleSheets()
 {
     if (!ensureShadowRootRareData()->styleSheets())
         m_shadowRootRareData->setStyleSheets(StyleSheetList::create(this));
 
     return m_shadowRootRareData->styleSheets();
 }
 
 }