1 files changed, 7 insertions, 0 deletions
diff --git a/Source/WebCore/fileapi/WebKitBlobBuilder.cpp b/Source/WebCore/fileapi/WebKitBlobBuilder.cpp
index c08e5fab7..d073c36ff 100644
--- a/Source/WebCore/fileapi/WebKitBlobBuilder.cpp
+++ b/Source/WebCore/fileapi/WebKitBlobBuilder.cpp
@@ -33,7 +33,9 @@
 #include "WebKitBlobBuilder.h"
 
 #include "Blob.h"
+#include "Document.h"
 #include "ExceptionCode.h"
+#include "FeatureObserver.h"
 #include "File.h"
 #include "HistogramSupport.h"
 #include "LineEnding.h"
@@ -61,6 +63,11 @@ PassRefPtr<WebKitBlobBuilder> WebKitBlobBuilder::create(ScriptExecutionContext*
     String message("BlobBuilder is deprecated. Use \"Blob\" constructor instead.");
     context->addConsoleMessage(JSMessageSource, LogMessageType, WarningMessageLevel, message);
 
+    if (context->isDocument()) {
+        Document* document = static_cast<Document*>(context);
+        FeatureObserver::observe(document->domWindow(), FeatureObserver::LegacyBlobBuilder);
+    }
+
     return adoptRef(new WebKitBlobBuilder());
 }