Move attributes-related API from UniqueElementData to AttributeCollection

Source/core/html/HTMLSelectElement.cpp

Index: Source/core/html/HTMLSelectElement.cpp
diff --git a/Source/core/html/HTMLSelectElement.cpp b/Source/core/html/HTMLSelectElement.cpp
index f6ecf4f839dcf973bdfd7731b2e537ae8f922f4f..febc74d4704be53e236741833b99a457b780bed3 100644
--- a/Source/core/html/HTMLSelectElement.cpp
+++ b/Source/core/html/HTMLSelectElement.cpp
@@ -334,7 +334,7 @@ void HTMLSelectElement::parseAttribute(const QualifiedName& name, const AtomicSt
         AtomicString attrSize = AtomicString::number(size);
         if (attrSize != value) {
             // FIXME: This is horribly factored.
-            if (Attribute* sizeAttribute = ensureUniqueElementData().findAttributeByName(sizeAttr))
+            if (Attribute* sizeAttribute = ensureUniqueElementData().attributes().find(sizeAttr))
                 sizeAttribute->setValue(attrSize);
         }
         size = std::max(size, 1);