[BackgroundSync] Trigger Background Sync events when Chrome is backgrounded on Android

content/browser/background_sync/background_sync_manager.h

Index: content/browser/background_sync/background_sync_manager.h
diff --git a/content/browser/background_sync/background_sync_manager.h b/content/browser/background_sync/background_sync_manager.h
index 673f41f98cb1f2733d7f767964063a048e875f5c..884a6dfb8546a141a11d695341f8c50cb6b40914 100644
--- a/content/browser/background_sync/background_sync_manager.h
+++ b/content/browser/background_sync/background_sync_manager.h
@@ -96,6 +96,10 @@ class CONTENT_EXPORT BackgroundSyncManager
                              const GURL& pattern) override;
   void OnStorageWiped() override;
 
+  BackgroundSyncNetworkObserver* GetNetworkObserverForTesting() {
+    return network_observer_.get();
+  }
+
  protected:
   // A registration might be referenced by the client longer than
   // the BackgroundSyncManager needs to keep track of it (e.g., the event has
@@ -327,6 +331,7 @@ class CONTENT_EXPORT BackgroundSyncManager
       const StatusCallback& callback);
 
   SWIdToRegistrationsMap active_registrations_;
+
   CacheStorageScheduler op_scheduler_;
   scoped_refptr<ServiceWorkerContextWrapper> service_worker_context_;
   bool disabled_;