Style invalidation support for :first/last/only-child.

third_party/WebKit/Source/core/dom/ContainerNode.h

Index: third_party/WebKit/Source/core/dom/ContainerNode.h
diff --git a/third_party/WebKit/Source/core/dom/ContainerNode.h b/third_party/WebKit/Source/core/dom/ContainerNode.h
index 3e252b61625929123b65f4aebb91305ccac20c25..fd76f81fdf222e5284d76e713c17240ecb41ac16 100644
--- a/third_party/WebKit/Source/core/dom/ContainerNode.h
+++ b/third_party/WebKit/Source/core/dom/ContainerNode.h
@@ -54,6 +54,13 @@ enum DynamicRestyleFlags {
     AffectedByLastChildRules = 1 << 11,
 
     NumberOfDynamicRestyleFlags = 12,
+
+    ChildrenAffectedByStructuralRules = ChildrenAffectedByFirstChildRules
+        | ChildrenAffectedByLastChildRules
+        | ChildrenAffectedByDirectAdjacentRules
+        | ChildrenAffectedByIndirectAdjacentRules
+        | ChildrenAffectedByForwardPositionalRules
+        | ChildrenAffectedByBackwardPositionalRules
 };
 
 enum SubtreeModificationAction {
@@ -158,7 +165,7 @@ public:
     // FIXME: These methods should all be renamed to something better than "check",
     // since it's not clear that they alter the style bits of siblings and children.
     enum SiblingCheckType { FinishedParsingChildren, SiblingElementInserted, SiblingElementRemoved };
-    void checkForSiblingStyleChanges(SiblingCheckType, Node* changedNode, Node* nodeBeforeChange, Node* nodeAfterChange);
+    void checkForSiblingStyleChanges(SiblingCheckType, Element* changedElement, Node* nodeBeforeChange, Node* nodeAfterChange);
     void recalcDescendantStyles(StyleRecalcChange);
 
     bool childrenSupportStyleSharing() const { return !hasRestyleFlags(); }