Add ref count to service workers for extension API.

content/public/browser/service_worker_context.h

Index: content/public/browser/service_worker_context.h
diff --git a/content/public/browser/service_worker_context.h b/content/public/browser/service_worker_context.h
index 72650154c721daaa19b9511aabc62f9ff028e167..3514de98393c928c35349effc78267eb126e5c35 100644
--- a/content/public/browser/service_worker_context.h
+++ b/content/public/browser/service_worker_context.h
@@ -14,6 +14,8 @@
 
 namespace content {
 
+class StoragePartition;
+
 // Represents the per-StoragePartition ServiceWorker data.
 class ServiceWorkerContext {
  public:
@@ -38,6 +40,13 @@ class ServiceWorkerContext {
   // Must be called from the IO thread.
   static bool IsExcludedHeaderNameForFetchEvent(const std::string& header_name);
 
+  CONTENT_EXPORT static void IncrementEmbeddedWorkerRefCount(
+      StoragePartition* storage_partition,
+      int embedded_worker_id);
+  CONTENT_EXPORT static void DecrementEmbeddedWorkerRefCount(
+      StoragePartition* storage_partition,
+      int embedded_worker_id);
+
   // Equivalent to calling navigator.serviceWorker.register(script_url, {scope:
   // pattern}) from a renderer, except that |pattern| is an absolute URL instead
   // of relative to some current origin.  |callback| is passed true when the JS