Add WorkerScriptLoaded message to support attaching DevTools while starting ServiceWorker.

content/browser/service_worker/embedded_worker_registry.cc

Index: content/browser/service_worker/embedded_worker_registry.cc
diff --git a/content/browser/service_worker/embedded_worker_registry.cc b/content/browser/service_worker/embedded_worker_registry.cc
index 82b9bb0397b63b2bfba37239102f9b26975012ac..a549281ce33c78342bab23b03e8f88cceccdd212 100644
--- a/content/browser/service_worker/embedded_worker_registry.cc
+++ b/content/browser/service_worker/embedded_worker_registry.cc
@@ -84,6 +84,17 @@ void EmbeddedWorkerRegistry::Shutdown() {
   }
 }
 
+void EmbeddedWorkerRegistry::OnWorkerScriptLoaded(int process_id,
+                                                  int embedded_worker_id) {
+  WorkerInstanceMap::iterator found = worker_map_.find(embedded_worker_id);
+  if (found == worker_map_.end()) {
+    LOG(ERROR) << "Worker " << embedded_worker_id << " not registered";
+    return;
+  }
+  DCHECK_EQ(found->second->process_id(), process_id);
+  found->second->OnScriptLoaded();
+}
+
 void EmbeddedWorkerRegistry::OnWorkerStarted(
     int process_id, int thread_id, int embedded_worker_id) {
   DCHECK(!ContainsKey(worker_process_map_, process_id) ||