Refactor ElementShadow by separating v0 related features as ElementShadowV0

third_party/WebKit/Source/core/dom/shadow/ElementShadow.h

Index: third_party/WebKit/Source/core/dom/shadow/ElementShadow.h
diff --git a/third_party/WebKit/Source/core/dom/shadow/ElementShadow.h b/third_party/WebKit/Source/core/dom/shadow/ElementShadow.h
index 3a4fbb1fd402a8c5b3f52b4ab99e2a53479e8e1d..c6f0506645d01bd9e2bbe8865a939d91d184a867 100644
--- a/third_party/WebKit/Source/core/dom/shadow/ElementShadow.h
+++ b/third_party/WebKit/Source/core/dom/shadow/ElementShadow.h
@@ -28,48 +28,44 @@
 #define ElementShadow_h
 
 #include "core/CoreExport.h"
-#include "core/dom/shadow/InsertionPoint.h"
-#include "core/dom/shadow/SelectRuleFeatureSet.h"
 #include "core/dom/shadow/ShadowRoot.h"
 #include "platform/heap/Handle.h"
-#include "wtf/HashMap.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
+class ElementShadowV0;
+
 class CORE_EXPORT ElementShadow final : public GarbageCollectedFinalized<ElementShadow> {
     WTF_MAKE_NONCOPYABLE(ElementShadow);
 public:
     static ElementShadow* create();
     ~ElementShadow();
 
-    Element& host() const;
+    Element& host() const { DCHECK(m_shadowRoot); return m_shadowRoot->host(); }
+
+    // TODO(hayato): Remove youngestShadowRoot() and oldestShadowRoot() from ElementShadow
     ShadowRoot& youngestShadowRoot() const;
     ShadowRoot& oldestShadowRoot() const { DCHECK(m_shadowRoot); return *m_shadowRoot; }
+
     ElementShadow* containingShadow() const;
 
     ShadowRoot& addShadowRoot(Element& shadowHost, ShadowRootType);
 
-    bool hasSameStyles(const ElementShadow*) const;
+    bool hasSameStyles(const ElementShadow&) const;
 
     void attach(const Node::AttachContext&);
     void detach(const Node::AttachContext&);
 
     void distributeIfNeeded();
+
     void setNeedsDistributionRecalc();
     bool needsDistributionRecalc() const { return m_needsDistributionRecalc; }
 
-    bool isV1() const { return youngestShadowRoot().isV1(); };
-    bool isOpenOrV0() const { return youngestShadowRoot().isOpenOrV0(); };
+    bool isV1() const { return youngestShadowRoot().isV1(); }
+    bool isOpenOrV0() const { return youngestShadowRoot().isOpenOrV0(); }
 
-    // For only v0
-    void willAffectSelector();
-    const SelectRuleFeatureSet& ensureSelectFeatureSet();
-
-    const InsertionPoint* finalDestinationInsertionPointFor(const Node*) const;
-    const DestinationInsertionPoints* destinationInsertionPointsFor(const Node*) const;
-
-    void didDistributeNode(const Node*, InsertionPoint*);
+    ElementShadowV0& v0() const { DCHECK(m_elementShadowV0); return *m_elementShadowV0; }
 
     DECLARE_TRACE();
     DECLARE_TRACE_WRAPPERS();
@@ -78,39 +74,17 @@ private:
     ElementShadow();
 
     void appendShadowRoot(ShadowRoot&);
-
     void distribute();
-    void clearDistributionV0();
-
-    void distributeV0();
-    void distributeV1();
-
-    void collectSelectFeatureSetFrom(ShadowRoot&);
-    void distributeNodeChildrenTo(InsertionPoint*, ContainerNode*);
-
-    bool needsSelectFeatureSet() const { return m_needsSelectFeatureSet; }
-    void setNeedsSelectFeatureSet() { m_needsSelectFeatureSet = true; }
 
+    Member<ElementShadowV0> m_elementShadowV0;
     Member<ShadowRoot> m_shadowRoot;
     bool m_needsDistributionRecalc;
-
-    // For only v0
-    using NodeToDestinationInsertionPoints = HeapHashMap<Member<const Node>, Member<DestinationInsertionPoints>>;
-    NodeToDestinationInsertionPoints m_nodeToInsertionPoints;
-    SelectRuleFeatureSet m_selectFeatures;
-    bool m_needsSelectFeatureSet;
 };
 
-inline Element& ElementShadow::host() const
-{
-    DCHECK(m_shadowRoot);
-    return m_shadowRoot->host();
-}
-
 inline ShadowRoot* Node::youngestShadowRoot() const
 {
     if (!isElementNode())
-        return 0;
+        return nullptr;
     return toElement(this)->youngestShadowRoot();
 }
 
@@ -118,14 +92,14 @@ inline ShadowRoot* Element::youngestShadowRoot() const
 {
     if (ElementShadow* shadow = this->shadow())
         return &shadow->youngestShadowRoot();
-    return 0;
+    return nullptr;
 }
 
 inline ElementShadow* ElementShadow::containingShadow() const
 {
     if (ShadowRoot* parentRoot = host().containingShadowRoot())
         return parentRoot->owner();
-    return 0;
+    return nullptr;
 }
 
 inline void ElementShadow::distributeIfNeeded()