Avoid calling hasAttribute() and then getAttribute() for performance

Source/core/editing/EditingStyle.cpp

 /*
  * Copyright (C) 2007, 2008, 2009 Apple Computer, Inc.
  * Copyright (C) 2010, 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 272 matching lines @@
 
 void HTMLAttributeEquivalent::addToStyle(Element* element, EditingStyle* style) const
 {
     if (RefPtrWillBeRawPtr<CSSValue> value = attributeValueAsCSSValue(element))
         style->setProperty(m_propertyID, value->cssText());
 }
 
 PassRefPtrWillBeRawPtr<CSSValue> HTMLAttributeEquivalent::attributeValueAsCSSValue(Element* element) const
 {
     ASSERT(element);
-    if (!element->hasAttribute(m_attrName))
+    const AtomicString& value = element->getAttribute(m_attrName);
+    if (value.isNull())
         return nullptr;
 
     RefPtr<MutableStylePropertySet> dummyStyle;
     dummyStyle = MutableStylePropertySet::create();
-    dummyStyle->setProperty(m_propertyID, element->getAttribute(m_attrName));
+    dummyStyle->setProperty(m_propertyID, value);
     return dummyStyle->getPropertyCSSValue(m_propertyID);
 }
 
 class HTMLFontSizeEquivalent FINAL : public HTMLAttributeEquivalent {
 public:
     static PassOwnPtr<HTMLFontSizeEquivalent> create()
     {
         return adoptPtr(new HTMLFontSizeEquivalent());
     }
     virtual PassRefPtrWillBeRawPtr<CSSValue> attributeValueAsCSSValue(Element*) const OVERRIDE;
 
 private:
     HTMLFontSizeEquivalent();
 };
 
 HTMLFontSizeEquivalent::HTMLFontSizeEquivalent()
     : HTMLAttributeEquivalent(CSSPropertyFontSize, HTMLNames::fontTag, HTMLNames::sizeAttr)
 {
 }
 
 PassRefPtrWillBeRawPtr<CSSValue> HTMLFontSizeEquivalent::attributeValueAsCSSValue(Element* element) const
 {
     ASSERT(element);
-    if (!element->hasAttribute(m_attrName))
+    const AtomicString& value = element->getAttribute(m_attrName);
+    if (value.isNull())
         return nullptr;
     CSSValueID size;
-    if (!HTMLFontElement::cssValueFromFontSizeNumber(element->getAttribute(m_attrName), size))
+    if (!HTMLFontElement::cssValueFromFontSizeNumber(value, size))
         return nullptr;
     return CSSPrimitiveValue::createIdentifier(size);
 }
 
 float EditingStyle::NoFontDelta = 0.0f;
 
 EditingStyle::EditingStyle()
     : m_shouldUseFixedDefaultFontSize(false)
     , m_fontSizeDelta(NoFontDelta)
 {
@@ skipping 1296 matching lines @@
 {
     for (Node* ancestor = node; ancestor; ancestor = ancestor->parentNode()) {
         RefPtr<CSSComputedStyleDeclaration> ancestorStyle = CSSComputedStyleDeclaration::create(ancestor);
         if (!hasTransparentBackgroundColor(ancestorStyle.get()))
             return ancestorStyle->getPropertyCSSValue(CSSPropertyBackgroundColor);
     }
     return nullptr;
 }
 
 }