Call ContainerNode::checkForSiblingStyleChanges() for Element insertion / removal only

Source/core/dom/ContainerNode.cpp

Index: Source/core/dom/ContainerNode.cpp
diff --git a/Source/core/dom/ContainerNode.cpp b/Source/core/dom/ContainerNode.cpp
index 6d8dc594f20539c21e4f8d93fbd9c4eee9d1dbf5..64147ab5075edb9f79868beb61351cfbaaf6e225 100644
--- a/Source/core/dom/ContainerNode.cpp
+++ b/Source/core/dom/ContainerNode.cpp
@@ -312,8 +312,7 @@ void ContainerNode::parserInsertBefore(PassRefPtrWillBeRawPtr<Node> newChild, No
 
     ChildListMutationScope(*this).childAdded(*newChild);
 
-    ChildrenChange change = {ChildInserted, newChild->previousSibling(), &nextChild, ChildrenChangeSourceParser};
-    childrenChanged(change);
+    childrenChanged(ChildrenChange::forInsertion(*newChild, ChildrenChangeSourceParser));
 
     notifyNodeInserted(*newChild);
 }
@@ -568,8 +567,7 @@ PassRefPtrWillBeRawPtr<Node> ContainerNode::removeChild(PassRefPtrWillBeRawPtr<N
         Node* prev = child->previousSibling();
         Node* next = child->nextSibling();
         removeBetween(prev, next, *child);
-        ChildrenChange change = {ChildRemoved, prev, next, ChildrenChangeSourceAPI};
-        childrenChanged(change);
+        childrenChanged(ChildrenChange::forRemoval(*child, prev, next, ChildrenChangeSourceAPI));
         notifyNodeRemoved(*child);
     }
     dispatchSubtreeModifiedEvent();
@@ -616,8 +614,7 @@ void ContainerNode::parserRemoveChild(Node& oldChild)
 
     removeBetween(prev, next, oldChild);
 
-    ChildrenChange change = {ChildRemoved, prev, next, ChildrenChangeSourceParser};
-    childrenChanged(change);
+    childrenChanged(ChildrenChange::forRemoval(oldChild, prev, next, ChildrenChangeSourceParser));
     notifyNodeRemoved(oldChild);
 }
 
@@ -751,8 +748,6 @@ void ContainerNode::parserAppendChild(PassRefPtrWillBeRawPtr<Node> newChild)
     if (document() != newChild->document())
         document().adoptNode(newChild.get(), ASSERT_NO_EXCEPTION);
 
-    Node* last = m_lastChild;
-
     {
         NoEventDispatchAssertion assertNoEventDispatch;
         ScriptForbiddenScope forbidScript;
@@ -763,8 +758,7 @@ void ContainerNode::parserAppendChild(PassRefPtrWillBeRawPtr<Node> newChild)
         ChildListMutationScope(*this).childAdded(*newChild);
     }
 
-    ChildrenChange change = {ChildInserted, last, nullptr, ChildrenChangeSourceParser};
-    childrenChanged(change);
+    childrenChanged(ChildrenChange::forInsertion(*newChild, ChildrenChangeSourceParser));
     notifyNodeInserted(*newChild);
 }
 
@@ -844,7 +838,7 @@ void ContainerNode::childrenChanged(const ChildrenChange& change)
     if (!change.byParser && change.type != TextChanged)
         document().updateRangesAfterChildrenChanged(this);
     invalidateNodeListCachesInAncestors();
-    if (change.type == ChildInserted && !childNeedsStyleRecalc()) {
+    if (change.isChildInsertion() && !childNeedsStyleRecalc()) {
         setChildNeedsStyleRecalc();
         markAncestorsWithChildNeedsStyleRecalc();
     }
@@ -1191,8 +1185,7 @@ void ContainerNode::updateTreeAfterInsertion(Node& child)
 
     ChildListMutationScope(*this).childAdded(child);
 
-    ChildrenChange change = {ChildInserted, child.previousSibling(), child.nextSibling(), ChildrenChangeSourceAPI};
-    childrenChanged(change);
+    childrenChanged(ChildrenChange::forInsertion(child, ChildrenChangeSourceAPI));
 
     notifyNodeInserted(child);
 
@@ -1278,11 +1271,13 @@ void ContainerNode::checkForSiblingStyleChanges(SiblingCheckType changeType, Nod
         RenderStyle* elementAfterChangeStyle = elementAfterChange ? elementAfterChange->renderStyle() : 0;
 
         // This is the element insertion as first child element case.
-        if (firstChildElement != elementAfterChange && elementAfterChangeStyle && elementAfterChangeStyle->firstChildState())
+        if (firstChildElement != elementAfterChange && elementAfterChangeStyle && elementAfterChangeStyle->firstChildState()) {
+            ASSERT(changeType == SiblingElementInserted);
             elementAfterChange->setNeedsStyleRecalc(SubtreeStyleChange);
+        }
 
         // This is the first child element removal case.
-        if (changeType == SiblingRemoved && firstChildElement == elementAfterChange && firstChildElement && (!firstChildElementStyle || !firstChildElementStyle->firstChildState()))
+        if (changeType == SiblingElementRemoved && firstChildElement == elementAfterChange && firstChildElement && (!firstChildElementStyle || !firstChildElementStyle->firstChildState()))
             firstChildElement->setNeedsStyleRecalc(SubtreeStyleChange);
     }
 
@@ -1298,12 +1293,14 @@ void ContainerNode::checkForSiblingStyleChanges(SiblingCheckType changeType, Nod
         RenderStyle* elementBeforeChangeStyle = elementBeforeChange ? elementBeforeChange->renderStyle() : 0;
 
         // This is the element insertion as last child element case.
-        if (lastChildElement != elementBeforeChange && elementBeforeChangeStyle && elementBeforeChangeStyle->lastChildState())
+        if (lastChildElement != elementBeforeChange && elementBeforeChangeStyle && elementBeforeChangeStyle->lastChildState()) {
+            ASSERT(SiblingElementInserted);
             elementBeforeChange->setNeedsStyleRecalc(SubtreeStyleChange);
+        }
 
         // This is the last child element removal case. The parser callback case is similar to node removal as well in that we need to change the last child
         // to match now.
-        if ((changeType == SiblingRemoved || changeType == FinishedParsingChildren) && lastChildElement == elementBeforeChange && lastChildElement && (!lastChildElementStyle || !lastChildElementStyle->lastChildState()))
+        if ((changeType == SiblingElementRemoved || changeType == FinishedParsingChildren) && lastChildElement == elementBeforeChange && lastChildElement && (!lastChildElementStyle || !lastChildElementStyle->lastChildState()))
             lastChildElement->setNeedsStyleRecalc(SubtreeStyleChange);
     }