Use downloadToFile option when XHR downloads a Blob

Source/core/inspector/InspectorPageAgent.cpp

Index: Source/core/inspector/InspectorPageAgent.cpp
diff --git a/Source/core/inspector/InspectorPageAgent.cpp b/Source/core/inspector/InspectorPageAgent.cpp
index 51f34a4baad00791969311c8a6eacd217e689107..4a070797fb31f7a88ef3c2e0a551db9eded5b9e4 100644
--- a/Source/core/inspector/InspectorPageAgent.cpp
+++ b/Source/core/inspector/InspectorPageAgent.cpp
@@ -128,6 +128,9 @@ static bool prepareResourceBuffer(Resource* cachedResource, bool* hasZeroSize)
     if (!cachedResource)
         return false;
 
+    if (cachedResource->dataBufferingPolicy() == DoNotBufferData)
+        return false;
+
     // Zero-sized resources don't have data at all -- so fake the empty buffer, instead of indicating error by returning 0.
     if (!cachedResource->encodedSize()) {
         *hasZeroSize = true;