BackgroundSyncManager tracks client registrations

content/browser/background_sync/background_sync_manager.cc

Index: content/browser/background_sync/background_sync_manager.cc
diff --git a/content/browser/background_sync/background_sync_manager.cc b/content/browser/background_sync/background_sync_manager.cc
index 018bbae5ab270ecfc3905a191a9fbb48dd63cb93..49cf468410408631dc1827b1c125afebc8fb374c 100644
--- a/content/browser/background_sync/background_sync_manager.cc
+++ b/content/browser/background_sync/background_sync_manager.cc
@@ -13,6 +13,7 @@
 #include "content/browser/background_sync/background_sync_network_observer.h"
 #include "content/browser/background_sync/background_sync_power_observer.h"
 #include "content/browser/background_sync/background_sync_registration_options.h"
+#include "content/browser/background_sync/client_background_sync_registration.h"
 #include "content/browser/service_worker/service_worker_context_wrapper.h"
 #include "content/browser/service_worker/service_worker_storage.h"
 #include "content/public/browser/browser_thread.h"
@@ -21,11 +22,23 @@
 #include "content/browser/android/background_sync_launcher_android.h"
 #endif
 
+namespace content {
+
 namespace {
+
 const char kBackgroundSyncUserDataKey[] = "BackgroundSyncUserData";
+
+void PostErrorResponse(
+    BackgroundSyncStatus status,
+    const BackgroundSyncManager::StatusAndRegistrationCallback& callback) {
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE,
+      base::Bind(
+          callback, status,
+          base::Passed(scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
 }
 
-namespace content {
+}  // namespace
 
 BackgroundSyncManager::BackgroundSyncRegistrations::
     BackgroundSyncRegistrations()
@@ -50,6 +63,13 @@ scoped_ptr<BackgroundSyncManager> BackgroundSyncManager::Create(
 BackgroundSyncManager::~BackgroundSyncManager() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
+  // This could race in the extremely unlikely case that the
+  // BackgroundSyncManager is deleted before a dispatched sync request is able
+  // to call BackgroundSyncServiceImpl::TrackRegistration.
+  // TODO(jkarlin): Stop the RenderProcessHost mojo registry when
+  // StoragePartition is gone.
+  DCHECK(client_registration_ids_.IsEmpty());
+
   service_worker_context_->RemoveObserver(this);
 }
 
@@ -87,9 +107,7 @@ void BackgroundSyncManager::Register(
         options.periodicity, registration_could_fire,
         BackgroundSyncMetrics::REGISTRATION_IS_NOT_DUPLICATE,
         BACKGROUND_SYNC_STATUS_STORAGE_ERROR);
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
-                              BackgroundSyncRegistration()));
+    PostErrorResponse(BACKGROUND_SYNC_STATUS_STORAGE_ERROR, callback);
     return;
   }
 
@@ -99,30 +117,6 @@ void BackgroundSyncManager::Register(
                  MakeStatusAndRegistrationCompletion(callback)));
 }
 
-void BackgroundSyncManager::Unregister(
-    int64 sw_registration_id,
-    const std::string& sync_registration_tag,
-    SyncPeriodicity periodicity,
-    BackgroundSyncRegistration::RegistrationId sync_registration_id,
-    const StatusCallback& callback) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-
-  if (disabled_) {
-    BackgroundSyncMetrics::CountUnregister(
-        periodicity, BACKGROUND_SYNC_STATUS_STORAGE_ERROR);
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR));
-    return;
-  }
-
-  RegistrationKey registration_key(sync_registration_tag, periodicity);
-
-  op_scheduler_.ScheduleOperation(base::Bind(
-      &BackgroundSyncManager::UnregisterImpl, weak_ptr_factory_.GetWeakPtr(),
-      sw_registration_id, registration_key, sync_registration_id, periodicity,
-      MakeStatusCompletion(callback)));
-}
-
 void BackgroundSyncManager::GetRegistration(
     int64 sw_registration_id,
     const std::string& sync_registration_tag,
@@ -131,9 +125,7 @@ void BackgroundSyncManager::GetRegistration(
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   if (disabled_) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
-                              BackgroundSyncRegistration()));
+    PostErrorResponse(BACKGROUND_SYNC_STATUS_STORAGE_ERROR, callback);
     return;
   }
 
@@ -153,8 +145,12 @@ void BackgroundSyncManager::GetRegistrations(
 
   if (disabled_) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
-                              std::vector<BackgroundSyncRegistration>()));
+        FROM_HERE,
+        base::Bind(
+            callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
+            base::Passed(
+                scoped_ptr<ScopedVector<ClientBackgroundSyncRegistration>>()
+                    .Pass())));
     return;
   }
 
@@ -164,6 +160,18 @@ void BackgroundSyncManager::GetRegistrations(
                  periodicity, MakeStatusAndRegistrationsCompletion(callback)));
 }
 
+bool BackgroundSyncManager::HasClientRegistration(
+    BackgroundSyncRegistration::RegistrationId sync_id) const {
+  return client_registration_ids_.Lookup(sync_id) != nullptr;
+}
+
+void BackgroundSyncManager::ReleaseClientRegistration(
+    BackgroundSyncRegistration::RegistrationId sync_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(client_registration_ids_.Lookup(sync_id));
+  client_registration_ids_.Remove(sync_id);
+}
+
 void BackgroundSyncManager::OnRegistrationDeleted(int64 registration_id,
                                                   const GURL& pattern) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
@@ -261,8 +269,11 @@ void BackgroundSyncManager::InitDidGetDataFromBackend(
 
         RegistrationKey registration_key(registration_proto.tag(),
                                          registration_proto.periodicity());
-        BackgroundSyncRegistration* registration =
-            &registrations->registration_map[registration_key];
+
+        scoped_refptr<RefCountedRegistration> ref_registration(
+            new RefCountedRegistration());
+        registrations->registration_map[registration_key] = ref_registration;
+        BackgroundSyncRegistration* registration = ref_registration->value();
 
         BackgroundSyncRegistrationOptions* options = registration->options();
         options->tag = registration_proto.tag();
@@ -315,9 +326,7 @@ void BackgroundSyncManager::RegisterImpl(
         options.periodicity, registration_could_fire,
         BackgroundSyncMetrics::REGISTRATION_IS_NOT_DUPLICATE,
         BACKGROUND_SYNC_STATUS_STORAGE_ERROR);
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
-                              BackgroundSyncRegistration()));
+    PostErrorResponse(BACKGROUND_SYNC_STATUS_STORAGE_ERROR, callback);
     return;
   }
 
@@ -328,31 +337,28 @@ void BackgroundSyncManager::RegisterImpl(
         options.periodicity, registration_could_fire,
         BackgroundSyncMetrics::REGISTRATION_IS_NOT_DUPLICATE,
         BACKGROUND_SYNC_STATUS_NO_SERVICE_WORKER);
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE,
-        base::Bind(callback, BACKGROUND_SYNC_STATUS_NO_SERVICE_WORKER,
-                   BackgroundSyncRegistration()));
+    PostErrorResponse(BACKGROUND_SYNC_STATUS_NO_SERVICE_WORKER, callback);
     return;
   }
 
   if (!sw_registration->active_version()->HasWindowClients()) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_NOT_ALLOWED,
-                              BackgroundSyncRegistration()));
+    PostErrorResponse(BACKGROUND_SYNC_STATUS_NOT_ALLOWED, callback);
     return;
   }
 
-  BackgroundSyncRegistration* existing_registration =
+  RefCountedRegistration* existing_registration_ref =
       LookupRegistration(sw_registration_id, RegistrationKey(options));
-  if (existing_registration &&
-      existing_registration->options()->Equals(options)) {
+  if (existing_registration_ref &&
+      existing_registration_ref->value()->options()->Equals(options)) {
+    BackgroundSyncRegistration* existing_registration =
+        existing_registration_ref->value();
     if (existing_registration->sync_state() == SYNC_STATE_FAILED) {
       existing_registration->set_sync_state(SYNC_STATE_PENDING);
       StoreRegistrations(
           sw_registration_id,
           base::Bind(&BackgroundSyncManager::RegisterDidStore,
                      weak_ptr_factory_.GetWeakPtr(), sw_registration_id,
-                     *existing_registration, callback));
+                     make_scoped_refptr(existing_registration_ref), callback));
       return;
     }
 
@@ -363,27 +369,33 @@ void BackgroundSyncManager::RegisterImpl(
         BACKGROUND_SYNC_STATUS_OK);
 
     base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_OK,
-                              *existing_registration));
+        FROM_HERE,
+        base::Bind(
+            callback, BACKGROUND_SYNC_STATUS_OK,
+            base::Passed(
+                CreateClientRegistration(*existing_registration_ref).Pass())));
     return;
   }
 
-  BackgroundSyncRegistration new_registration;
-  *new_registration.options() = options;
+  scoped_refptr<RefCountedRegistration> new_ref_registration(
+      new RefCountedRegistration());
+  BackgroundSyncRegistration* new_registration = new_ref_registration->value();
+
+  *new_registration->options() = options;
 
   BackgroundSyncRegistrations* registrations =
       &sw_to_registrations_map_[sw_registration_id];
-  new_registration.set_id(registrations->next_id++);
+  new_registration->set_id(registrations->next_id++);
 
   AddRegistrationToMap(sw_registration_id,
                        sw_registration->pattern().GetOrigin(),
-                       new_registration);
+                       new_ref_registration);
 
   StoreRegistrations(
       sw_registration_id,
       base::Bind(&BackgroundSyncManager::RegisterDidStore,
                  weak_ptr_factory_.GetWeakPtr(), sw_registration_id,
-                 new_registration, callback));
+                 new_ref_registration, callback));
 }
 
 void BackgroundSyncManager::DisableAndClearManager(
@@ -441,7 +453,8 @@ void BackgroundSyncManager::DisableAndClearManagerClearedOne(
                                                 base::Bind(barrier_closure));
 }
 
-BackgroundSyncRegistration* BackgroundSyncManager::LookupRegistration(
+BackgroundSyncManager::RefCountedRegistration*
+BackgroundSyncManager::LookupRegistration(
     int64 sw_registration_id,
     const RegistrationKey& registration_key) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
@@ -460,7 +473,7 @@ BackgroundSyncRegistration* BackgroundSyncManager::LookupRegistration(
   if (key_and_registration_iter == registrations.registration_map.end())
     return nullptr;
 
-  return &key_and_registration_iter->second;
+  return key_and_registration_iter->second.get();
 }
 
 void BackgroundSyncManager::StoreRegistrations(
@@ -477,7 +490,7 @@ void BackgroundSyncManager::StoreRegistrations(
 
   for (const auto& key_and_registration : registrations.registration_map) {
     const BackgroundSyncRegistration& registration =
-        key_and_registration.second;
+        *key_and_registration.second->value();
     BackgroundSyncRegistrationProto* registration_proto =
         registrations_proto.add_registration();
     registration_proto->set_id(registration.id());
@@ -499,27 +512,28 @@ void BackgroundSyncManager::StoreRegistrations(
 
 void BackgroundSyncManager::RegisterDidStore(
     int64 sw_registration_id,
-    const BackgroundSyncRegistration& new_registration,
+    const scoped_refptr<RefCountedRegistration>& new_registration_ref,
     const StatusAndRegistrationCallback& callback,
     ServiceWorkerStatusCode status) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
+  const BackgroundSyncRegistration* new_registration =
+      new_registration_ref->value();
+
   // For UMA, determine here whether the sync could fire immediately
   BackgroundSyncMetrics::RegistrationCouldFire registration_could_fire =
-      AreOptionConditionsMet(*new_registration.options())
+      AreOptionConditionsMet(*new_registration->options())
           ? BackgroundSyncMetrics::REGISTRATION_COULD_FIRE
           : BackgroundSyncMetrics::REGISTRATION_COULD_NOT_FIRE;
 
   if (status == SERVICE_WORKER_ERROR_NOT_FOUND) {
     // The service worker registration is gone.
     BackgroundSyncMetrics::CountRegister(
-        new_registration.options()->periodicity, registration_could_fire,
+        new_registration->options()->periodicity, registration_could_fire,
         BackgroundSyncMetrics::REGISTRATION_IS_NOT_DUPLICATE,
         BACKGROUND_SYNC_STATUS_STORAGE_ERROR);
     sw_to_registrations_map_.erase(sw_registration_id);
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
-                              BackgroundSyncRegistration()));
+    PostErrorResponse(BACKGROUND_SYNC_STATUS_STORAGE_ERROR, callback);
     return;
   }
 
@@ -527,23 +541,25 @@ void BackgroundSyncManager::RegisterDidStore(
     LOG(ERROR) << "BackgroundSync failed to store registration due to backend "
                   "failure.";
     BackgroundSyncMetrics::CountRegister(
-        new_registration.options()->periodicity, registration_could_fire,
+        new_registration->options()->periodicity, registration_could_fire,
         BackgroundSyncMetrics::REGISTRATION_IS_NOT_DUPLICATE,
         BACKGROUND_SYNC_STATUS_STORAGE_ERROR);
-    DisableAndClearManager(base::Bind(callback,
-                                      BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
-                                      BackgroundSyncRegistration()));
+    DisableAndClearManager(base::Bind(
+        callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
+        base::Passed(scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
     return;
   }
 
   BackgroundSyncMetrics::CountRegister(
-      new_registration.options()->periodicity, registration_could_fire,
+      new_registration->options()->periodicity, registration_could_fire,
       BackgroundSyncMetrics::REGISTRATION_IS_NOT_DUPLICATE,
       BACKGROUND_SYNC_STATUS_OK);
   FireReadyEvents();
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
-      base::Bind(callback, BACKGROUND_SYNC_STATUS_OK, new_registration));
+      base::Bind(callback, BACKGROUND_SYNC_STATUS_OK,
+                 base::Passed(
+                     CreateClientRegistration(*new_registration_ref).Pass())));
 }
 
 void BackgroundSyncManager::RemoveRegistrationFromMap(
@@ -561,15 +577,15 @@ void BackgroundSyncManager::RemoveRegistrationFromMap(
 void BackgroundSyncManager::AddRegistrationToMap(
     int64 sw_registration_id,
     const GURL& origin,
-    const BackgroundSyncRegistration& sync_registration) {
+    const scoped_refptr<RefCountedRegistration>& sync_registration) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  DCHECK(sync_registration.IsValid());
+  DCHECK(sync_registration->value()->IsValid());
 
   BackgroundSyncRegistrations* registrations =
       &sw_to_registrations_map_[sw_registration_id];
   registrations->origin = origin;
 
-  RegistrationKey registration_key(sync_registration);
+  RegistrationKey registration_key(*sync_registration->value());
   registrations->registration_map[registration_key] = sync_registration;
 }
 
@@ -596,20 +612,52 @@ void BackgroundSyncManager::GetDataFromBackend(
 }
 
 void BackgroundSyncManager::FireOneShotSync(
-    const BackgroundSyncRegistration& registration,
+    const RefCountedRegistration& registration,
     const scoped_refptr<ServiceWorkerVersion>& active_version,
     const ServiceWorkerVersion::StatusCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  active_version->DispatchSyncEvent(
-      mojo::ConvertTo<SyncRegistrationPtr>(registration), callback);
+  // The ServiceWorkerVersion doesn't know when the client (javascript) is done
+  // with the registration so don't give it a ClientBackgroundSyncRegistration.
+  // The render process must call BackgroundSyncServiceImpl::TrackRegistration
+  // which creates the corresponding ClientBackgroundSyncRegistration. In the
+  // unlikely event that the render process is killed before TrackRegistration
+  // is called, the manager will hold the reference until it is destroyed.
+  // The ~BackgroundSyncManager DCHECKS verify that this is uncommon.
+  SyncRegistrationPtr sync_registration =
+      mojo::ConvertTo<SyncRegistrationPtr>(*registration.value());
+  scoped_refptr<const RefCountedRegistration>* ptr =
+      new scoped_refptr<const RefCountedRegistration>(&registration);
+  sync_registration->id = client_registration_ids_.Add(ptr);
+
+  active_version->DispatchSyncEvent(sync_registration.Pass(), callback);
 }
 
-void BackgroundSyncManager::UnregisterImpl(
+void BackgroundSyncManager::Unregister(
     int64 sw_registration_id,
-    const RegistrationKey& registration_key,
+    SyncPeriodicity periodicity,
     BackgroundSyncRegistration::RegistrationId sync_registration_id,
+    const StatusCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  if (disabled_) {
+    BackgroundSyncMetrics::CountUnregister(
+        periodicity, BACKGROUND_SYNC_STATUS_STORAGE_ERROR);
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR));
+    return;
+  }
+
+  op_scheduler_.ScheduleOperation(base::Bind(
+      &BackgroundSyncManager::UnregisterImpl, weak_ptr_factory_.GetWeakPtr(),
+      sw_registration_id, periodicity, sync_registration_id,
+      MakeStatusCompletion(callback)));
+}
+
+void BackgroundSyncManager::UnregisterImpl(
+    int64 sw_registration_id,
     SyncPeriodicity periodicity,
+    BackgroundSyncRegistration::RegistrationId sync_registration_id,
     const StatusCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
@@ -621,10 +669,21 @@ void BackgroundSyncManager::UnregisterImpl(
     return;
   }
 
-  const BackgroundSyncRegistration* existing_registration =
+  scoped_refptr<const RefCountedRegistration>* hosted_registration_ref =
+      client_registration_ids_.Lookup(sync_registration_id);
+  DCHECK(hosted_registration_ref);
+
+  const BackgroundSyncRegistration* hosted_registration =
+      (*hosted_registration_ref)->value();
+
+  RegistrationKey registration_key(hosted_registration->options()->tag,
+                                   periodicity);
+
+  const RefCountedRegistration* existing_registration =
       LookupRegistration(sw_registration_id, registration_key);
+
   if (!existing_registration ||
-      existing_registration->id() != sync_registration_id) {
+      existing_registration->value()->id() != hosted_registration->id()) {
     BackgroundSyncMetrics::CountUnregister(periodicity,
                                            BACKGROUND_SYNC_STATUS_NOT_FOUND);
     base::ThreadTaskRunnerHandle::Get()->PostTask(
@@ -678,24 +737,21 @@ void BackgroundSyncManager::GetRegistrationImpl(
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   if (disabled_) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
-                              BackgroundSyncRegistration()));
+    PostErrorResponse(BACKGROUND_SYNC_STATUS_STORAGE_ERROR, callback);
     return;
   }
 
-  const BackgroundSyncRegistration* out_registration =
+  const RefCountedRegistration* registration =
       LookupRegistration(sw_registration_id, registration_key);
-  if (!out_registration) {
-    base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_NOT_FOUND,
-                              BackgroundSyncRegistration()));
+  if (!registration) {
+    PostErrorResponse(BACKGROUND_SYNC_STATUS_NOT_FOUND, callback);
     return;
   }
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
-      base::Bind(callback, BACKGROUND_SYNC_STATUS_OK, *out_registration));
+      base::Bind(callback, BACKGROUND_SYNC_STATUS_OK,
+                 base::Passed(CreateClientRegistration(*registration).Pass())));
 }
 
 void BackgroundSyncManager::GetRegistrationsImpl(
@@ -704,12 +760,13 @@ void BackgroundSyncManager::GetRegistrationsImpl(
     const StatusAndRegistrationsCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  std::vector<BackgroundSyncRegistration> out_registrations;
+  scoped_ptr<ScopedVector<ClientBackgroundSyncRegistration>> out_registrations(
+      new ScopedVector<ClientBackgroundSyncRegistration>());
 
   if (disabled_) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
-                              out_registrations));
+                              base::Passed(out_registrations.Pass())));
     return;
   }
 
@@ -719,16 +776,18 @@ void BackgroundSyncManager::GetRegistrationsImpl(
   if (it != sw_to_registrations_map_.end()) {
     const BackgroundSyncRegistrations& registrations = it->second;
     for (const auto& tag_and_registration : registrations.registration_map) {
-      const BackgroundSyncRegistration& registration =
-          tag_and_registration.second;
-      if (registration.options()->periodicity == periodicity)
-        out_registrations.push_back(registration);
+      const RefCountedRegistration& registration =
+          *tag_and_registration.second.get();
+      if (registration.value()->options()->periodicity == periodicity) {
+        out_registrations->push_back(
+            CreateClientRegistration(registration).release());
+      }
     }
   }
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE,
-      base::Bind(callback, BACKGROUND_SYNC_STATUS_OK, out_registrations));
+      FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_OK,
+                            base::Passed(out_registrations.Pass())));
 }
 
 bool BackgroundSyncManager::AreOptionConditionsMet(
@@ -762,7 +821,7 @@ void BackgroundSyncManager::SchedulePendingRegistrations() {
     for (const auto& key_and_registration :
          sw_id_and_registrations.second.registration_map) {
       const BackgroundSyncRegistration& registration =
-          key_and_registration.second;
+          *key_and_registration.second->value();
       if (registration.sync_state() == SYNC_STATE_PENDING) {
         if (registration.options()->periodicity == SYNC_ONE_SHOT) {
           keep_browser_alive_for_one_shot = true;
@@ -812,7 +871,8 @@ void BackgroundSyncManager::FireReadyEventsImpl(const base::Closure& callback) {
     const int64 service_worker_id = sw_id_and_registrations.first;
     for (auto& key_and_registration :
          sw_id_and_registrations.second.registration_map) {
-      BackgroundSyncRegistration* registration = &key_and_registration.second;
+      BackgroundSyncRegistration* registration =
+          key_and_registration.second->value();
       if (IsRegistrationReadyToFire(*registration)) {
         sw_id_and_keys_to_fire.push_back(
             std::make_pair(service_worker_id, key_and_registration.first));
@@ -845,14 +905,15 @@ void BackgroundSyncManager::FireReadyEventsImpl(const base::Closure& callback) {
 
     for (const auto& sw_id_and_key : sw_id_and_keys_to_fire) {
       int64 service_worker_id = sw_id_and_key.first;
-      const BackgroundSyncRegistration* registration =
+      const RefCountedRegistration* registration =
           LookupRegistration(service_worker_id, sw_id_and_key.second);
+      DCHECK(registration);
 
       service_worker_context_->FindRegistrationForId(
           service_worker_id, sw_to_registrations_map_[service_worker_id].origin,
           base::Bind(&BackgroundSyncManager::FireReadyEventsDidFindRegistration,
                      weak_ptr_factory_.GetWeakPtr(), sw_id_and_key.second,
-                     registration->id(), events_fired_barrier_closure,
+                     registration->value()->id(), events_fired_barrier_closure,
                      events_completed_barrier_closure));
     }
   }
@@ -877,8 +938,9 @@ void BackgroundSyncManager::FireReadyEventsDidFindRegistration(
     return;
   }
 
-  BackgroundSyncRegistration* registration =
+  const RefCountedRegistration* registration =
       LookupRegistration(service_worker_registration->id(), registration_key);
+  DCHECK(registration);
 
   FireOneShotSync(
       *registration, service_worker_registration->active_version(),
@@ -924,14 +986,17 @@ void BackgroundSyncManager::EventCompleteImpl(
     return;
   }
 
-  BackgroundSyncRegistration* registration =
+  RefCountedRegistration* registration_ref =
       LookupRegistration(service_worker_id, key);
-  if (!registration || registration->id() != sync_registration_id) {
+  if (!registration_ref ||
+      registration_ref->value()->id() != sync_registration_id) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                   base::Bind(callback));
     return;
   }
 
+  BackgroundSyncRegistration* registration = registration_ref->value();
+
   // The event ran to completion, we should count it, no matter what happens
   // from here.
   BackgroundSyncMetrics::RecordEventResult(registration->options()->periodicity,
@@ -1011,6 +1076,20 @@ void BackgroundSyncManager::OnStorageWipedImpl(const base::Closure& callback) {
   InitImpl(callback);
 }
 
+scoped_ptr<ClientBackgroundSyncRegistration>
+BackgroundSyncManager::CreateClientRegistration(
+    const RefCountedRegistration& registration) {
+  scoped_ptr<ClientBackgroundSyncRegistration> out_registration(
+      new ClientBackgroundSyncRegistration(this));
+  *out_registration->options() = *registration.value()->options();
+  out_registration->set_sync_state(registration.value()->sync_state());
+
+  scoped_refptr<const RefCountedRegistration>* ptr =
+      new scoped_refptr<const RefCountedRegistration>(&registration);
+  out_registration->set_id(client_registration_ids_.Add(ptr));
+  return out_registration.Pass();
+}
+
 void BackgroundSyncManager::OnNetworkChanged() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
@@ -1023,6 +1102,7 @@ void BackgroundSyncManager::OnPowerChanged() {
   FireReadyEvents();
 }
 
+// TODO(jkarlin): Figure out how to pass scoped_ptrs with this.
 template <typename CallbackT, typename... Params>
 void BackgroundSyncManager::CompleteOperationCallback(const CallbackT& callback,
                                                       Params... parameters) {
@@ -1032,6 +1112,26 @@ void BackgroundSyncManager::CompleteOperationCallback(const CallbackT& callback,
   op_scheduler_.CompleteOperationAndRunNext();
 }
 
+void BackgroundSyncManager::CompleteStatusAndRegistrationCallback(
+    StatusAndRegistrationCallback callback,
+    BackgroundSyncStatus status,
+    scoped_ptr<ClientBackgroundSyncRegistration> result) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  callback.Run(status, result.Pass());
+  op_scheduler_.CompleteOperationAndRunNext();
+}
+
+void BackgroundSyncManager::CompleteStatusAndRegistrationsCallback(
+    StatusAndRegistrationsCallback callback,
+    BackgroundSyncStatus status,
+    scoped_ptr<ScopedVector<ClientBackgroundSyncRegistration>> results) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  callback.Run(status, results.Pass());
+  op_scheduler_.CompleteOperationAndRunNext();
+}
+
 base::Closure BackgroundSyncManager::MakeEmptyCompletion() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
@@ -1052,10 +1152,9 @@ BackgroundSyncManager::MakeStatusAndRegistrationCompletion(
     const StatusAndRegistrationCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  return base::Bind(&BackgroundSyncManager::CompleteOperationCallback<
-                        StatusAndRegistrationCallback, BackgroundSyncStatus,
-                        const BackgroundSyncRegistration&>,
-                    weak_ptr_factory_.GetWeakPtr(), callback);
+  return base::Bind(
+      &BackgroundSyncManager::CompleteStatusAndRegistrationCallback,
+      weak_ptr_factory_.GetWeakPtr(), callback);
 }
 
 BackgroundSyncManager::StatusAndRegistrationsCallback
@@ -1063,10 +1162,9 @@ BackgroundSyncManager::MakeStatusAndRegistrationsCompletion(
     const StatusAndRegistrationsCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  return base::Bind(&BackgroundSyncManager::CompleteOperationCallback<
-                        StatusAndRegistrationsCallback, BackgroundSyncStatus,
-                        const std::vector<BackgroundSyncRegistration>&>,
-                    weak_ptr_factory_.GetWeakPtr(), callback);
+  return base::Bind(
+      &BackgroundSyncManager::CompleteStatusAndRegistrationsCallback,
+      weak_ptr_factory_.GetWeakPtr(), callback);
 }
 
 BackgroundSyncManager::StatusCallback