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 e05591a6399644dc78e58b2b38dcb5df89a976de..8f831ed9bc43d0be0a6744c322c54a56f661e8d1 100644
--- a/Source/core/inspector/InspectorPageAgent.cpp
+++ b/Source/core/inspector/InspectorPageAgent.cpp
@@ -129,6 +129,9 @@ 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;