Track lastTextNode during rebuildLayoutTree.

third_party/WebKit/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
@@ skipping 1271 matching lines @@
 void ContainerNode::setRestyleFlag(DynamicRestyleFlags mask) {
   DCHECK(isElementNode() || isShadowRoot());
   ensureRareData().setRestyleFlag(mask);
 }
 
 void ContainerNode::recalcDescendantStyles(StyleRecalcChange change) {
   DCHECK(document().inStyleRecalc());
   DCHECK(change >= UpdatePseudoElements || childNeedsStyleRecalc());
   DCHECK(!needsStyleRecalc());
 
-  // This loop is deliberately backwards because we use insertBefore in the
-  // layout 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 = nullptr;
   for (Node* child = lastChild(); child; child = child->previousSibling()) {
     if (child->isTextNode()) {
-      toText(child)->recalcTextStyle(change, lastTextNode);
-      lastTextNode = toText(child);
+      toText(child)->recalcTextStyle(change);
     } else if (child->isElementNode()) {
       Element* element = toElement(child);
       if (element->shouldCallRecalcStyle(change))
-        element->recalcStyle(change, lastTextNode);
+        element->recalcStyle(change);
       else if (element->supportsStyleSharing())
         styleResolver.addToStyleSharingList(*element);
-      if (element->layoutObject())
-        lastTextNode = nullptr;
     }
   }
 }
 
 void ContainerNode::rebuildChildrenLayoutTrees() {
   DCHECK(!needsReattachLayoutTree());
 
+  // This loop is deliberately backwards because we use insertBefore in the
+  // layout tree, and want to avoid a potentially n^2 loop to find the insertion
+  // point while building the layout tree.  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
+  Text* lastTextNode = nullptr;
   for (Node* child = lastChild(); child; child = child->previousSibling()) {
-    if (child->needsReattachLayoutTree() ||
-        child->childNeedsReattachLayoutTree()) {
-      if (child->isTextNode())
-        toText(child)->rebuildTextLayoutTree();
-      else if (child->isElementNode())
-        toElement(child)->rebuildLayoutTree();
+    bool rebuildChild = child->needsReattachLayoutTree() ||
+                        child->childNeedsReattachLayoutTree();
+    if (child->isTextNode()) {
+      Text* textNode = toText(child);
+      if (rebuildChild)
+        textNode->rebuildTextLayoutTree(lastTextNode);
+      lastTextNode = textNode;
+    } else if (child->isElementNode()) {
+      Element* element = toElement(child);
+      if (rebuildChild)
+        element->rebuildLayoutTree(lastTextNode);
+      if (element->layoutObject())
+        lastTextNode = nullptr;
     }
   }
   // This is done in ContainerNode::attachLayoutTree but will never be cleared
   // if we don't enter ContainerNode::attachLayoutTree so we do it here.
   clearChildNeedsStyleRecalc();
   clearChildNeedsReattachLayoutTree();
 }
 
 void ContainerNode::checkForSiblingStyleChanges(SiblingCheckType changeType,
                                                 Element* changedElement,
@@ skipping 167 matching lines @@
     return true;
 
   if (node->isElementNode() && toElement(node)->shadow())
     return true;
 
   return false;
 }
 #endif
 
 }  // namespace blink