Optimize Element::attributeChanged()

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)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1091 matching lines @@
     if (ElementShadow* parentElementShadow = shadowWhereNodeCanBeDistributed(*this)) {
         if (shouldInvalidateDistributionWhenAttributeChanged(parentElementShadow, name, newValue))
             parentElementShadow->setNeedsDistributionRecalc();
     }
 
     parseAttribute(name, newValue);
 
     document().incDOMTreeVersion();
 
     StyleResolver* styleResolver = document().styleResolver();
-    bool testShouldInvalidateStyle = inActiveDocument() && styleResolver && styleChangeType() < SubtreeStyleChange;
-
-    if (isStyledElement()) {
-        if (name == styleAttr) {
-            styleAttributeChanged(newValue, reason);
-        } else if (isPresentationAttribute(name)) {
-            elementData()->m_presentationAttributeStyleIsDirty = true;
-            setNeedsStyleRecalc(LocalStyleChange, StyleChangeReasonForTracing::fromAttribute(name));
-        }
-    }
 
     if (name == HTMLNames::idAttr) {
         AtomicString oldId = elementData()->idForStyleResolution();
         AtomicString newId = makeIdForStyleResolution(newValue, document().inQuirksMode());
         if (newId != oldId) {
             elementData()->setIdForStyleResolution(newId);
+            bool testShouldInvalidateStyle = inActiveDocument() && styleResolver && styleChangeType() < SubtreeStyleChange;

[Mike West, 2015/06/07 13:59:43]

Nit: You can fold this into the `if` on the next line.

[sof, 2015/06/07 19:01:15]

Or give it a better name :)

             if (testShouldInvalidateStyle)
                 document().styleEngine().idChangedForElement(oldId, newId, *this);
         }
     } else if (name == classAttr) {
         classAttributeChanged(newValue);
     } else if (name == HTMLNames::nameAttr) {
         setHasName(!newValue.isNull());
+    } else if (isStyledElement()) {
+        if (name == styleAttr) {
+            styleAttributeChanged(newValue, reason);
+        } else if (isPresentationAttribute(name)) {
+            elementData()->m_presentationAttributeStyleIsDirty = true;
+            setNeedsStyleRecalc(LocalStyleChange, StyleChangeReasonForTracing::fromAttribute(name));
+        }
     }
 
     invalidateNodeListCachesInAncestors(&name, this);
 
     // If there is currently no StyleResolver, we can't be sure that this attribute change won't affect style.
     if (!styleResolver)
         setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::fromAttribute(name));
 
     if (AXObjectCache* cache = document().existingAXObjectCache())
         cache->handleAttributeChanged(name, this);
@@ skipping 2308 matching lines @@
 {
 #if ENABLE(OILPAN)
     if (hasRareData())
         visitor->trace(elementRareData());
     visitor->trace(m_elementData);
 #endif
     ContainerNode::trace(visitor);
 }
 
 } // namespace blink