HTML MessagePort as mojo::MessagePipeHandle

content/child/blob_storage/blob_transport_controller.cc

Index: content/child/blob_storage/blob_transport_controller.cc
diff --git a/content/child/blob_storage/blob_transport_controller.cc b/content/child/blob_storage/blob_transport_controller.cc
index 1b01792079edee0775759258403c09ecddfb653d..4f6d14543d70fd2e2b276d135db836cf4f8bb764 100644
--- a/content/child/blob_storage/blob_transport_controller.cc
+++ b/content/child/blob_storage/blob_transport_controller.cc
@@ -181,6 +181,10 @@ void BlobTransportController::InitiateBlobTransfer(
                  base::Unretained(BlobTransportController::GetInstance()), uuid,
                  base::Passed(std::move(consolidation)),
                  base::Passed(std::move(main_runner))));
+
+  // Measure how much jank the following synchronous IPC introduces.
+  SCOPED_UMA_HISTOGRAM_TIMER("Storage.Blob.RegisterBlobTime");
+
   sender->Send(
       new BlobStorageMsg_RegisterBlob(uuid, content_type, "", descriptions));
 }