In issue 917527 support was added for pre-provisioned origin IDs. As MediaDrmStorageImpl gets a unique origin ID asynchronously, it is possible for multiple calls to MediaDrmStorageImpl::Initialize() to occur concurrently. The code detects this and uses the first origin ID returned, but subsequent origin IDs are simply dropped. As pre-provisioned origin IDs may have used resources on the device, the unused origin ID should not be dropped but cleaned up somehow.

As MediaDrmStorageImpl doesn't have access to MediaDrmBridge to unprovision the ID, maybe it could get added to the preference using a dummy domain and then would get cleaned up when Clear Browsing Data is called.