Refactoring: Extract DocumentInit for capture Document construction parameter.

Source/core/xml/XMLHttpRequest.cpp

Index: Source/core/xml/XMLHttpRequest.cpp
diff --git a/Source/core/xml/XMLHttpRequest.cpp b/Source/core/xml/XMLHttpRequest.cpp
index 4d25329ef260a13b0a5deaf6a0438b344f6c0038..7ac35d7ae9a96d6a057ea51b4ae9c14859fbc4b5 100644
--- a/Source/core/xml/XMLHttpRequest.cpp
+++ b/Source/core/xml/XMLHttpRequest.cpp
@@ -244,9 +244,9 @@ Document* XMLHttpRequest::responseXML(ExceptionCode& ec)
             m_responseDocument = 0;
         } else {
             if (isHTML)
-                m_responseDocument = HTMLDocument::create(0, m_url);
+                m_responseDocument = HTMLDocument::create(DocumentInit(m_url));
             else
-                m_responseDocument = Document::create(0, m_url);
+                m_responseDocument = Document::create(DocumentInit(m_url));
             // FIXME: Set Last-Modified.
             m_responseDocument->setContent(m_responseText.flattenToString());
             m_responseDocument->setSecurityOrigin(securityOrigin());