Make Element::attributes() less error-prone and simplify call sites

Source/core/html/HTMLObjectElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 169 matching lines @@
     // in a PARAM tag. See <http://java.sun.com/products/plugin/1.2/docs/tags.html>. This means
     // we have to explicitly suppress the tag's CODEBASE attribute if there is none in a PARAM,
     // else our Java plugin will misinterpret it. [4004531]
     String codebase;
     if (MIMETypeRegistry::isJavaAppletMIMEType(serviceType)) {
         codebase = "codebase";
         uniqueParamNames.add(codebase.impl()); // pretend we found it in a PARAM already
     }
 
     // Turn the attributes of the <object> element into arrays, but don't override <param> values.
-    if (hasAttributes()) {
-        AttributeCollection attributes = this->attributes();
-        AttributeCollection::const_iterator end = attributes.end();
-        for (AttributeCollection::const_iterator it = attributes.begin(); it != end; ++it) {
-            const AtomicString& name = it->name().localName();
-            if (!uniqueParamNames.contains(name.impl())) {
-                paramNames.append(name.string());
-                paramValues.append(it->value().string());
-            }
+    AttributeCollection attributes = this->attributes();
+    AttributeCollection::const_iterator end = attributes.end();
+    for (AttributeCollection::const_iterator it = attributes.begin(); it != end; ++it) {
+        const AtomicString& name = it->name().localName();
+        if (!uniqueParamNames.contains(name.impl())) {
+            paramNames.append(name.string());
+            paramValues.append(it->value().string());
         }
     }
 
     mapDataParamToSrc(&paramNames, &paramValues);
 
     // HTML5 says that an object resource's URL is specified by the object's data
     // attribute, not by a param element. However, for compatibility, allow the
     // resource's URL to be given by a param named "src", "movie", "code" or "url"
     // if we know that resource points to a plug-in.
     if (url.isEmpty() && !urlParameter.isEmpty()) {
@@ skipping 251 matching lines @@
 {
     return fastHasAttribute(usemapAttr);
 }
 
 bool HTMLObjectElement::useFallbackContent() const
 {
     return HTMLPlugInElement::useFallbackContent() || m_useFallbackContent;
 }
 
 }