Share recalcChildStyle between Element and ShadowRoot.

Source/core/dom/ContainerNode.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2013 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 1187 matching lines @@
 {
     return rareData()->hasRestyleFlags();
 }
 
 void ContainerNode::setRestyleFlag(DynamicRestyleFlags mask)
 {
     ASSERT(isElementNode() || isShadowRoot());
     ensureRareData().setRestyleFlag(mask);
 }
 
+void ContainerNode::recalcChildStyle(StyleRecalcChange change)
+{
+    ASSERT(document().inStyleRecalc());
+    ASSERT(change >= UpdatePseudoElements || childNeedsStyleRecalc());
+    ASSERT(!needsStyleRecalc());
+
+    if (change < Force && hasRareData() && childNeedsStyleRecalc())
+        checkForChildrenAdjacentRuleChanges();
+
+    // This loop is deliberately backwards because we use insertBefore in the rendering tree, and want to avoid
+    // a potentially n^2 loop to find the insertion point while resolving style. Having us start from the last
+    // child and work our way back means in the common case, we'll find the insertion point in O(1) time.
+    // See crbug.com/288225
+    StyleResolver& styleResolver = document().ensureStyleResolver();
+    Text* lastTextNode = 0;
+    for (Node* child = lastChild(); child; child = child->previousSibling()) {
+        if (child->isTextNode()) {
+            toText(child)->recalcTextStyle(change, lastTextNode);
+            lastTextNode = toText(child);
+        } else if (child->isElementNode()) {
+            Element* element = toElement(child);
+            if (element->shouldCallRecalcStyle(change))
+                element->recalcStyle(change, lastTextNode);
+            else if (element->supportsStyleSharing())
+                styleResolver.addToStyleSharingList(*element);
+            if (element->renderer())
+                lastTextNode = 0;
+        }
+    }
+}
+
 void ContainerNode::checkForChildrenAdjacentRuleChanges()
 {
     bool hasDirectAdjacentRules = childrenAffectedByDirectAdjacentRules();
     bool hasIndirectAdjacentRules = childrenAffectedByIndirectAdjacentRules();
 
     if (!hasDirectAdjacentRules && !hasIndirectAdjacentRules)
         return;
 
     unsigned forceCheckOfNextElementCount = 0;
     bool forceCheckOfAnyElementSibling = false;
@@ skipping 192 matching lines @@
         return true;
 
     if (node->isElementNode() && toElement(node)->shadow())
         return true;
 
     return false;
 }
 #endif
 
 } // namespace blink