Introduce WebServiceWorkerNetworkProvider::GetProviderID() and stop static casting

content/child/service_worker/service_worker_network_provider.cc

Index: content/child/service_worker/service_worker_network_provider.cc
diff --git a/content/child/service_worker/service_worker_network_provider.cc b/content/child/service_worker/service_worker_network_provider.cc
index 8372661ebc3373f98b007dff237fb3e6eb9881f0..ffac7fc35d06a88679b35621d00a05bae9302fce 100644
--- a/content/child/service_worker/service_worker_network_provider.cc
+++ b/content/child/service_worker/service_worker_network_provider.cc
@@ -80,6 +80,8 @@ class WebServiceWorkerNetworkProviderForFrame
     return provider_->IsControlledByServiceWorker();
   }
 
+  int GetProviderID() const override { return provider_->provider_id(); }
+
   int64_t ServiceWorkerID() override {
     if (provider_->context() && provider_->context()->controller())
       return provider_->context()->controller()->version_id();