BackgroundSyncManager tracks client registrations

content/child/background_sync/background_sync_provider_thread_proxy.h

Index: content/child/background_sync/background_sync_provider_thread_proxy.h
diff --git a/content/child/background_sync/background_sync_provider_thread_proxy.h b/content/child/background_sync/background_sync_provider_thread_proxy.h
index 5a319520f3f582b56568aa9e3eb519b16ab011d6..22985702602e1322384e7b8e5f89b2a356656de8 100644
--- a/content/child/background_sync/background_sync_provider_thread_proxy.h
+++ b/content/child/background_sync/background_sync_provider_thread_proxy.h
@@ -7,6 +7,7 @@
 
 #include "base/macros.h"
 #include "content/child/worker_task_runner.h"
+#include "content/common/background_sync_service.mojom.h"
 #include "third_party/WebKit/public/platform/modules/background_sync/WebSyncProvider.h"
 
 namespace base {
@@ -55,6 +56,16 @@ class BackgroundSyncProviderThreadProxy : public blink::WebSyncProvider,
       blink::WebSyncRegistration::Periodicity periodicity,
       blink::WebServiceWorkerRegistration* service_worker_registration,
       blink::WebSyncGetPermissionStatusCallbacks* callbacks);
+  // TODO(jkarlin): Rename to releaseRegistrationHandle.
+  void releaseRegistration(int64_t handle_id);
+
+  // Given |handle_id|, ask the provider for a new handle with the same
+  // underlying registration.
+  void DuplicateRegistrationHandle(
+      int64 handle_id,
+      int64 service_worker_registration_id,
+      const BackgroundSyncService::DuplicateRegistrationHandleCallback&
+          callback);
 
   // WorkerTaskRunner::Observer implementation.
   void OnWorkerRunLoopStopped() override;