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 fcdb8545689f440cd8d395d91af2d7568f04241d..9f1ae7062759b6e94b95b7df259039f4b6c602dd 100644
--- a/Source/core/inspector/InspectorPageAgent.cpp
+++ b/Source/core/inspector/InspectorPageAgent.cpp
@@ -130,6 +130,9 @@ 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;