Fixed perf regression by removing tree traversal for text sibling.

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

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index d1a185e5527a3c99ea73004ace5e1bb2bd12e6ec..3cfa5edca8318c507e77fd5062b8be33717e6a25 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -1287,13 +1287,13 @@ Element* Document::scrollingElement() {
 // We use HashMap::set over HashMap::add here as we want to
 // replace the ComputedStyle but not the Element if the Element is
 // already present.
-void Document::addNonAttachedStyle(Element& element,
-                                   RefPtr<ComputedStyle> computedStyle) {
-  m_nonAttachedStyle.set(&element, computedStyle);
+void Document::addStyleRecalcData(Element& element,
+                                  StyleRecalcData* styleRecalcData) {
+  m_styleRecalcDataMap.set(&element, styleRecalcData);
 }
 
-ComputedStyle* Document::getNonAttachedStyle(Element& element) {
-  return m_nonAttachedStyle.get(&element);
+StyleRecalcData* Document::getStyleRecalcData(Element& element) {
+  return m_styleRecalcDataMap.get(&element);
 }
 
 /*
@@ -1971,7 +1971,7 @@ void Document::updateStyle() {
 
   // Only retain the HashMap for the duration of StyleRecalc and
   // LayoutTreeConstruction.
-  m_nonAttachedStyle.clear();
+  m_styleRecalcDataMap.clear();
   clearChildNeedsStyleRecalc();
   clearChildNeedsReattachLayoutTree();
 
@@ -1983,7 +1983,7 @@ void Document::updateStyle() {
   DCHECK(!childNeedsReattachLayoutTree());
   DCHECK(inStyleRecalc());
   DCHECK_EQ(styleResolver(), &resolver);
-  DCHECK(m_nonAttachedStyle.isEmpty());
+  DCHECK(m_styleRecalcDataMap.isEmpty());
   m_lifecycle.advanceTo(DocumentLifecycle::StyleClean);
   if (shouldRecordStats) {
     TRACE_EVENT_END2("blink,blink_style", "Document::updateStyle",
@@ -6430,7 +6430,7 @@ DEFINE_TRACE(Document) {
   visitor->trace(m_snapCoordinator);
   visitor->trace(m_resizeObserverController);
   visitor->trace(m_propertyRegistry);
-  visitor->trace(m_nonAttachedStyle);
+  visitor->trace(m_styleRecalcDataMap);
   Supplementable<Document>::trace(visitor);
   TreeScope::trace(visitor);
   ContainerNode::trace(visitor);