Add ref count to service workers for extension API.

content/browser/service_worker/service_worker_context_wrapper.h

Index: content/browser/service_worker/service_worker_context_wrapper.h
diff --git a/content/browser/service_worker/service_worker_context_wrapper.h b/content/browser/service_worker/service_worker_context_wrapper.h
index 0285802834194f66fd3c299e56f1e4819e4305c9..caace4d8aecbb116b8264b04585e177101953512 100644
--- a/content/browser/service_worker/service_worker_context_wrapper.h
+++ b/content/browser/service_worker/service_worker_context_wrapper.h
@@ -186,6 +186,13 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
   // Must be called from the IO thread.
   bool OriginHasForeignFetchRegistrations(const GURL& origin);
 
+  static void IncrementEmbeddedWorkerRefCount(
+      StoragePartition* storage_partition,
+      int embedded_worker_id);
+  static void DecrementEmbeddedWorkerRefCount(
+      StoragePartition* storage_partition,
+      int embedded_worker_id);
+
  private:
   friend class BackgroundSyncManagerTest;
   friend class base::RefCountedThreadSafe<ServiceWorkerContextWrapper>;
@@ -200,6 +207,8 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
   friend class MockServiceWorkerContextWrapper;
 
   ~ServiceWorkerContextWrapper() override;
+  void IncrementEmbeddedWorkerRefCountOnIO(int embedded_worker_id);
+  void DecrementEmbeddedWorkerRefCountOnIO(int embedded_worker_id);
 
   void InitInternal(
       const base::FilePath& user_data_directory,