Add iterator object to iterate efficiently over an Element's attributes

Source/core/editing/markup.cpp

Index: Source/core/editing/markup.cpp
diff --git a/Source/core/editing/markup.cpp b/Source/core/editing/markup.cpp
index c256e91188405d72f9ab8d464a74648fae00aa19..53b195c1762bcf667a4a872059bf23b31a3e4504 100644
--- a/Source/core/editing/markup.cpp
+++ b/Source/core/editing/markup.cpp
@@ -112,11 +112,11 @@ static void completeURLs(DocumentFragment& fragment, const String& baseURL)
     for (Element* element = ElementTraversal::firstWithin(fragment); element; element = ElementTraversal::next(*element, &fragment)) {
         if (!element->hasAttributes())
             continue;
-        unsigned length = element->attributeCount();
-        for (unsigned i = 0; i < length; i++) {
-            const Attribute& attribute = element->attributeItem(i);
-            if (element->isURLAttribute(attribute) && !attribute.value().isEmpty())
-                changes.append(AttributeChange(element, attribute.name(), KURL(parsedBaseURL, attribute.value()).string()));
+        AttributeIteratorAccessor attributes = element->attributesIterator();
+        AttributeConstIterator end = attributes.end();
+        for (AttributeConstIterator it = attributes.begin(); it != end; ++it) {
+            if (element->isURLAttribute(**it) && !it->value().isEmpty())
+                changes.append(AttributeChange(element, it->name(), KURL(parsedBaseURL, it->value()).string()));
         }
     }
 
@@ -288,15 +288,18 @@ void StyledMarkupAccumulator::appendElement(StringBuilder& out, Element& element
     const bool documentIsHTML = element.document().isHTMLDocument();
     appendOpenTag(out, element, 0);
 
-    const unsigned length = element.hasAttributes() ? element.attributeCount() : 0;
     const bool shouldAnnotateOrForceInline = element.isHTMLElement() && (shouldAnnotate() || addDisplayInline);
     const bool shouldOverrideStyleAttr = shouldAnnotateOrForceInline || shouldApplyWrappingStyle(element);
-    for (unsigned i = 0; i < length; ++i) {
-        const Attribute& attribute = element.attributeItem(i);
-        // We'll handle the style attribute separately, below.
-        if (attribute.name() == styleAttr && shouldOverrideStyleAttr)
-            continue;
-        appendAttribute(out, element, attribute, 0);
+
+    if (element.hasAttributes()) {
+        AttributeIteratorAccessor attributes = element.attributesIterator();
+        AttributeConstIterator end = attributes.end();
+        for (AttributeConstIterator it = attributes.begin(); it != end; ++it) {
+            // We'll handle the style attribute separately, below.
+            if (it->name() == styleAttr && shouldOverrideStyleAttr)
+                continue;
+            appendAttribute(out, element, **it, 0);
+        }
     }
 
     if (shouldOverrideStyleAttr) {