Fixed perf regression by removing tree traversal for text sibling.

third_party/WebKit/Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc.
  * All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
@@ skipping 1815 matching lines @@
                                  isInTopLayer());
 
   return style.release();
 }
 
 PassRefPtr<ComputedStyle> Element::originalStyleForLayoutObject() {
   DCHECK(document().inStyleRecalc());
   return document().ensureStyleResolver().styleForElement(this);
 }
 
-void Element::recalcStyle(StyleRecalcChange change) {
+void Element::recalcStyle(StyleRecalcChange change, Text* nextTextSibling) {
   DCHECK(document().inStyleRecalc());
   DCHECK(!document().lifecycle().inDetach());
   DCHECK(!parentOrShadowHostNode()->needsStyleRecalc());
   DCHECK(inActiveDocument());
 
   if (hasCustomStyleCallbacks())
     willRecalcStyle(change);
 
   if (change >= IndependentInherit || needsStyleRecalc()) {
     if (hasRareData()) {
       ElementRareData* data = elementRareData();
       if (change != IndependentInherit)
         data->clearComputedStyle();
 
       if (change >= IndependentInherit) {
         if (ElementAnimations* elementAnimations = data->elementAnimations())
           elementAnimations->setAnimationStyleChange(false);
       }
     }
     if (parentComputedStyle())
-      change = recalcOwnStyle(change);
+      change = recalcOwnStyle(change, nextTextSibling);
     clearNeedsStyleRecalc();
     clearNeedsReattachLayoutTree();
   }
 
   // If we reattached we don't need to recalc the style of our descendants
   // anymore.
   if ((change >= UpdatePseudoElements && change < Reattach) ||
       childNeedsStyleRecalc()) {
     SelectorFilterParentScope filterScope(*this);
     StyleSharingDepthScope sharingScope(*this);
@@ skipping 42 matching lines @@
   const ComputedStyle* style = computedStyle();
   if (!style || style->animations() || style->transitions())
     return nullptr;
   RefPtr<ComputedStyle> newStyle = ComputedStyle::clone(*style);
   newStyle->propagateIndependentInheritedProperties(*parentStyle);
   INCREMENT_STYLE_STATS_COUNTER(document().styleEngine(),
                                 independentInheritedStylesPropagated, 1);
   return newStyle;
 }
 
-StyleRecalcChange Element::recalcOwnStyle(StyleRecalcChange change) {
+StyleRecalcChange Element::recalcOwnStyle(StyleRecalcChange change,
+                                          Text* nextTextSibling) {
   DCHECK(document().inStyleRecalc());
   DCHECK(!parentOrShadowHostNode()->needsStyleRecalc());
   DCHECK(change >= IndependentInherit || needsStyleRecalc());
   DCHECK(parentComputedStyle());
 
   RefPtr<ComputedStyle> oldStyle = mutableComputedStyle();
 
   // When propagating inherited changes, we don't need to do a full style recalc
   // if the only changed properties are independent. In this case, we can simply
   // set these directly on the ComputedStyle object.
   RefPtr<ComputedStyle> newStyle = propagateInheritedProperties(change);
   if (!newStyle)
     newStyle = styleForLayoutObject();
   DCHECK(newStyle);
 
   StyleRecalcChange localChange =
       ComputedStyle::stylePropagationDiff(oldStyle.get(), newStyle.get());
   if (localChange == NoChange) {
     INCREMENT_STYLE_STATS_COUNTER(document().styleEngine(), stylesUnchanged, 1);
   } else {
     INCREMENT_STYLE_STATS_COUNTER(document().styleEngine(), stylesChanged, 1);
   }
 
   if (localChange == Reattach) {
-    document().addNonAttachedStyle(*this, std::move(newStyle));
+    StyleReattachData styleReattachData;
+    styleReattachData.computedStyle = std::move(newStyle);
+    styleReattachData.nextTextSibling = nextTextSibling;
+    document().addStyleReattachData(*this, styleReattachData);
     setNeedsReattachLayoutTree();
     return rebuildLayoutTree();
   }
 
   DCHECK(oldStyle);
 
   if (localChange != NoChange)
     updateCallbackSelectors(oldStyle.get(), newStyle.get());
 
   if (LayoutObject* layoutObject = this->layoutObject()) {
@@ skipping 24 matching lines @@
     }
     if (oldStyle->hasPseudoElementStyle() || newStyle->hasPseudoElementStyle())
       return UpdatePseudoElements;
   }
 
   return localChange;
 }
 
 StyleRecalcChange Element::rebuildLayoutTree() {
   DCHECK(inActiveDocument());
+  StyleReattachData styleReattachData = document().getStyleReattachData(*this);
   AttachContext reattachContext;
-  reattachContext.resolvedStyle = document().getNonAttachedStyle(*this);
+  reattachContext.resolvedStyle = styleReattachData.computedStyle.get();
   bool layoutObjectWillChange = needsAttach() || layoutObject();
 
   // We are calling Element::rebuildLayoutTree() from inside
   // Element::recalcOwnStyle where we set the NeedsReattachLayoutTree
   // flag - so needsReattachLayoutTree() should always be true.
   DCHECK(parentNode());
   DCHECK(parentNode()->childNeedsReattachLayoutTree());
   DCHECK(needsReattachLayoutTree());
   reattachLayoutTree(reattachContext);
   // Since needsReattachLayoutTree() is always true we go into
   // reattachLayoutTree() which reattaches all the descendant
   // sub-trees. At this point no child should need reattaching.
   DCHECK(!childNeedsReattachLayoutTree());
 
   if (layoutObjectWillChange || layoutObject()) {
     // nextTextSibling is passed on to recalcStyle from recalcDescendantStyles
     // we can either traverse the current subtree from this node onwards
     // or store it.
     // The choice is between increased time and increased memory complexity.
-    reattachWhitespaceSiblingsIfNeeded(nextTextSibling());
+    reattachWhitespaceSiblingsIfNeeded(styleReattachData.nextTextSibling);
     return Reattach;
   }
   return ReattachNoLayoutObject;
 }
 
 void Element::updateCallbackSelectors(const ComputedStyle* oldStyle,
                                       const ComputedStyle* newStyle) {
   Vector<String> emptyVector;
   const Vector<String>& oldCallbackSelectors =
       oldStyle ? oldStyle->callbackSelectors() : emptyVector;
@@ skipping 2062 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(Element) {
   if (hasRareData()) {
     visitor->traceWrappers(elementRareData());
   }
   ContainerNode::traceWrappers(visitor);
 }
 
 }  // namespace blink