Measure usage of createObjectURL and srcObject

third_party/WebKit/Source/core/fileapi/URLFileAPI.cpp

Index: third_party/WebKit/Source/core/fileapi/URLFileAPI.cpp
diff --git a/third_party/WebKit/Source/core/fileapi/URLFileAPI.cpp b/third_party/WebKit/Source/core/fileapi/URLFileAPI.cpp
index 985a576fc2f4c8507fe9e99d7b9c304267533fce..9c3883462a54ee50ca0fc03080574a5d6ffea8ed 100644
--- a/third_party/WebKit/Source/core/fileapi/URLFileAPI.cpp
+++ b/third_party/WebKit/Source/core/fileapi/URLFileAPI.cpp
@@ -8,6 +8,7 @@
 #include "core/dom/DOMURL.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/fileapi/Blob.h"
+#include "core/frame/UseCounter.h"
 #include "core/html/PublicURLManager.h"
 
 namespace blink {
@@ -19,9 +20,13 @@ String URLFileAPI::createObjectURL(ExecutionContext* executionContext, Blob* blo
     DCHECK(executionContext);
 
     if (blob->isClosed()) {
+        // TODO(jsbell): The spec doesn't throw, but rather returns a blob: URL
+        // without adding it to the store.
         exceptionState.throwDOMException(InvalidStateError, String(blob->isFile() ? "File" : "Blob") + " has been closed.");
         return String();
     }
+
+    UseCounter::count(executionContext, UseCounter::CreateObjectURLBlob);
     return DOMURL::createPublicURL(executionContext, blob, blob->uuid());
 }