Have ChildFrameDisconnector / ChildListMutationScope deal with references

Source/core/dom/MutationObserverInterestGroup.h

Index: Source/core/dom/MutationObserverInterestGroup.h
diff --git a/Source/core/dom/MutationObserverInterestGroup.h b/Source/core/dom/MutationObserverInterestGroup.h
index 4950f31172935cd4f856659f30c47564017d4354..b149afcf935a364018f0dabf6caa95bce2b119d3 100644
--- a/Source/core/dom/MutationObserverInterestGroup.h
+++ b/Source/core/dom/MutationObserverInterestGroup.h
@@ -42,26 +42,26 @@ namespace WebCore {
 
 class MutationObserverInterestGroup {
 public:
-    static PassOwnPtr<MutationObserverInterestGroup> createForChildListMutation(Node* target)
+    static PassOwnPtr<MutationObserverInterestGroup> createForChildListMutation(Node& target)
     {
-        if (!target->document().hasMutationObserversOfType(MutationObserver::ChildList))
+        if (!target.document().hasMutationObserversOfType(MutationObserver::ChildList))
             return nullptr;
 
         MutationRecordDeliveryOptions oldValueFlag = 0;
         return createIfNeeded(target, MutationObserver::ChildList, oldValueFlag);
     }
 
-    static PassOwnPtr<MutationObserverInterestGroup> createForCharacterDataMutation(Node* target)
+    static PassOwnPtr<MutationObserverInterestGroup> createForCharacterDataMutation(Node& target)
     {
-        if (!target->document().hasMutationObserversOfType(MutationObserver::CharacterData))
+        if (!target.document().hasMutationObserversOfType(MutationObserver::CharacterData))
             return nullptr;
 
         return createIfNeeded(target, MutationObserver::CharacterData, MutationObserver::CharacterDataOldValue);
     }
 
-    static PassOwnPtr<MutationObserverInterestGroup> createForAttributesMutation(Node* target, const QualifiedName& attributeName)
+    static PassOwnPtr<MutationObserverInterestGroup> createForAttributesMutation(Node& target, const QualifiedName& attributeName)
     {
-        if (!target->document().hasMutationObserversOfType(MutationObserver::Attributes))
+        if (!target.document().hasMutationObserversOfType(MutationObserver::Attributes))
             return nullptr;
 
         return createIfNeeded(target, MutationObserver::Attributes, MutationObserver::AttributeOldValue, &attributeName);
@@ -71,7 +71,7 @@ public:
     void enqueueMutationRecord(PassRefPtr<MutationRecord>);
 
 private:
-    static PassOwnPtr<MutationObserverInterestGroup> createIfNeeded(Node* target, MutationObserver::MutationType, MutationRecordDeliveryOptions oldValueFlag, const QualifiedName* attributeName = 0);
+    static PassOwnPtr<MutationObserverInterestGroup> createIfNeeded(Node& target, MutationObserver::MutationType, MutationRecordDeliveryOptions oldValueFlag, const QualifiedName* attributeName = 0);
     MutationObserverInterestGroup(HashMap<MutationObserver*, MutationRecordDeliveryOptions>& observers, MutationRecordDeliveryOptions oldValueFlag);
 
     bool hasOldValue(MutationRecordDeliveryOptions options) { return options & m_oldValueFlag; }