Correct data size argument type in resource loading path to unsigned

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 69986e041d2e82d180eab8f692b98c05f61ad237..f9ef7321c32db0499be49587637d3bfddb1915e1 100644
--- a/Source/core/xml/XMLHttpRequest.cpp
+++ b/Source/core/xml/XMLHttpRequest.cpp
@@ -442,7 +442,7 @@ XMLHttpRequestUpload* XMLHttpRequest::upload()
     return m_upload.get();
 }
 
-void XMLHttpRequest::trackProgress(int length)
+void XMLHttpRequest::trackProgress(long long length)
 {
     m_receivedLength += length;
 
@@ -1392,7 +1392,7 @@ void XMLHttpRequest::didReceiveResponse(unsigned long identifier, const Resource
         m_finalResponseCharset = response.textEncodingName();
 }
 
-void XMLHttpRequest::parseDocumentChunk(const char* data, int len)
+void XMLHttpRequest::parseDocumentChunk(const char* data, unsigned len)
 {
     if (!m_responseDocumentParser) {
         ASSERT(!m_responseDocument);
@@ -1436,7 +1436,7 @@ PassOwnPtr<TextResourceDecoder> XMLHttpRequest::createDecoder() const
     return TextResourceDecoder::create("text/plain", "UTF-8");
 }
 
-void XMLHttpRequest::didReceiveData(const char* data, int len)
+void XMLHttpRequest::didReceiveData(const char* data, unsigned len)
 {
     ASSERT(!m_downloadingToFile);
 
@@ -1454,9 +1454,6 @@ void XMLHttpRequest::didReceiveData(const char* data, int len)
     if (!len)
         return;
 
-    if (len == -1)
-        len = strlen(data);
-
     if (m_responseTypeCode == ResponseTypeDocument && responseIsHTML()) {
         parseDocumentChunk(data, len);
     } else if (m_responseTypeCode == ResponseTypeDefault || m_responseTypeCode == ResponseTypeText || m_responseTypeCode == ResponseTypeJSON || m_responseTypeCode == ResponseTypeDocument) {