Use downloadToFile option when XHR downloads a Blob

Source/core/loader/FrameFetchContext.cpp

Index: Source/core/loader/FrameFetchContext.cpp
diff --git a/Source/core/loader/FrameFetchContext.cpp b/Source/core/loader/FrameFetchContext.cpp
index 885d1e86e38fc0f9a1c3e426bf8e6976e3a79e60..a42976c241fb67c6361f5c9b960784e2ef06e159 100644
--- a/Source/core/loader/FrameFetchContext.cpp
+++ b/Source/core/loader/FrameFetchContext.cpp
@@ -135,6 +135,13 @@ void FrameFetchContext::dispatchDidReceiveData(DocumentLoader*, unsigned long id
     InspectorInstrumentation::didReceiveData(m_frame, identifier, data, dataLength, encodedDataLength);
 }
 
+void FrameFetchContext::dispatchDidDownloadData(DocumentLoader*, unsigned long identifier, int dataLength, int encodedDataLength)
+{
+    if (Page* page = m_frame->page())
+        page->progress().incrementProgress(identifier, 0, dataLength);
+    InspectorInstrumentation::didReceiveData(m_frame, identifier, 0, dataLength, encodedDataLength);
+}
+
 void FrameFetchContext::dispatchDidFinishLoading(DocumentLoader* loader, unsigned long identifier, double finishTime)
 {
     if (Page* page = m_frame->page())