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..252b21bb211bde1d2cae37c71e07d7d44588d72b 100644
--- a/content/child/blob_storage/blob_transport_controller.cc
+++ b/content/child/blob_storage/blob_transport_controller.cc
@@ -181,8 +181,15 @@ void BlobTransportController::InitiateBlobTransfer(
                  base::Unretained(BlobTransportController::GetInstance()), uuid,
                  base::Passed(std::move(consolidation)),
                  base::Passed(std::move(main_runner))));
+
+  // Measure how much jank this synchronous IPC is introducing.
+  base::TimeTicks time_before = base::TimeTicks::Now();
+
   sender->Send(
       new BlobStorageMsg_RegisterBlob(uuid, content_type, "", descriptions));
+
+  base::TimeDelta time_delta = base::TimeTicks::Now() - time_before;
+  UMA_HISTOGRAM_TIMES("Storage.Blob.RegisterBlobTime", time_delta);
 }
 
 void BlobTransportController::OnMemoryRequest(