[Background Sync] Use Mojo IPC to fire background sync events

content/browser/service_worker/service_worker_version.h

Index: content/browser/service_worker/service_worker_version.h
diff --git a/content/browser/service_worker/service_worker_version.h b/content/browser/service_worker/service_worker_version.h
index d77ed99202c02013e012641c7be48c86996778c0..dbb30d156b69e6aafc1c95a85dd19ba6f5507869 100644
--- a/content/browser/service_worker/service_worker_version.h
+++ b/content/browser/service_worker/service_worker_version.h
@@ -21,6 +21,7 @@
 #include "base/timer/timer.h"
 #include "content/browser/service_worker/embedded_worker_instance.h"
 #include "content/browser/service_worker/service_worker_script_cache_map.h"
+#include "content/common/background_sync_service.mojom.h"
 #include "content/common/content_export.h"
 #include "content/common/service_worker/service_worker_status_code.h"
 #include "content/common/service_worker/service_worker_types.h"
@@ -209,6 +210,15 @@ class CONTENT_EXPORT ServiceWorkerVersion
   //
   // This must be called when the status() is ACTIVATED.
   void DispatchSyncEvent(const StatusCallback& callback);
+  void DispatchSyncEventOnUIThread(int render_process_id,
+                                   int thread_id,
+                                   const StatusCallback& callback);
+
+  // Handle callbacks from background sync events
+  void OnSyncEventFinished(const StatusCallback& callback,
+                           BackgroundSyncEventStatus status);
+  void FinishSyncEventOnIOThread(const StatusCallback& callback,
+                                 BackgroundSyncEventStatus status);
 
   // Sends notificationclick event to the associated embedded worker and
   // asynchronously calls |callback| when it errors out or it gets a response
@@ -354,7 +364,6 @@ class CONTENT_EXPORT ServiceWorkerVersion
     REQUEST_ACTIVATE,
     REQUEST_INSTALL,
     REQUEST_FETCH,
-    REQUEST_SYNC,
     REQUEST_NOTIFICATION_CLICK,
     REQUEST_PUSH,
     REQUEST_GEOFENCING,
@@ -416,8 +425,6 @@ class CONTENT_EXPORT ServiceWorkerVersion
   void OnFetchEventFinished(int request_id,
                             ServiceWorkerFetchEventResult result,
                             const ServiceWorkerResponse& response);
-  void OnSyncEventFinished(int request_id,
-                           blink::WebServiceWorkerEventResult result);
   void OnNotificationClickEventFinished(int request_id);
   void OnPushEventFinished(int request_id,
                            blink::WebServiceWorkerEventResult result);
@@ -523,7 +530,6 @@ class CONTENT_EXPORT ServiceWorkerVersion
   IDMap<StatusCallback, IDMapOwnPointer> activate_callbacks_;
   IDMap<StatusCallback, IDMapOwnPointer> install_callbacks_;
   IDMap<FetchCallback, IDMapOwnPointer> fetch_callbacks_;
-  IDMap<StatusCallback, IDMapOwnPointer> sync_callbacks_;
   IDMap<StatusCallback, IDMapOwnPointer> notification_click_callbacks_;
   IDMap<StatusCallback, IDMapOwnPointer> push_callbacks_;
   IDMap<StatusCallback, IDMapOwnPointer> geofencing_callbacks_;
@@ -568,6 +574,8 @@ class CONTENT_EXPORT ServiceWorkerVersion
   scoped_ptr<PingController> ping_controller_;
   scoped_ptr<Metrics> metrics_;
 
+  BackgroundSyncServiceClientPtr background_sync_client_;

[jkarlin, 2015/06/10 12:21:33]

Hmm, this whole class is IO and this one member is UI. Is it safe for this to be
deleted on the IO thread?

I recommend you make a new class that is to be accessed on the UI thread only
like so:

// All public methods must be called on UI thread. Can be constructed, owned,
and destructed on a separate thread.
class BackgroundSyncEventDispatcher : public
RefCountedThreadSafe<BackgroundSyncEventDispatcher,
BrowserThread::DeleteOnUIThread> {

public:
  // Dispatches the event and then runs |callback| on |task_runner| with the
result.
  DispatchSyncEvent(int render_process_id,
      int thread_id,
      const StatusCallback& callback, 
      const scoped_refptr<base::TaskRunner>& task_runner);

private:
  friend class base::RefCountedThreadSafe<BackgroundSyncEventDispatcher,
BrowserThread::DeleteOnUIThread>;
  ~BackgroundSyncEventDispatcher();

  BackgroundSyncServiceClientPtr background_sync_client_;
}

Then add a scoped_refptr<BackgroundSyncEventDispatcher> member to
ServiceWorkerVersion.

[iclelland, 2015/06/12 15:01:18]

Would a general ServiceWorkerEventDispatcher make more sense than a
BackgroundSyncEventDispatcher?
It may be premature, but if other services move to this model, then I think I'd
rather encourage authors to extend that class than create a PushEventDispatcher
class and a GeofenceEventDispatcher class, etc.

+
   base::WeakPtrFactory<ServiceWorkerVersion> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerVersion);