BackgroundSyncManager tracks client registrations

content/browser/background_sync/background_sync_manager.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/background_sync/background_sync_manager.h"
 
 #include "base/barrier_closure.h"
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
 #include "content/browser/background_sync/background_sync_metrics.h"
 #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"
 
 #if defined(OS_ANDROID)
 #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()
     : next_id(BackgroundSyncRegistration::kInitialId) {
 }
 
 BackgroundSyncManager::BackgroundSyncRegistrations::
     ~BackgroundSyncRegistrations() {
 }
 
 // static
 scoped_ptr<BackgroundSyncManager> BackgroundSyncManager::Create(
     const scoped_refptr<ServiceWorkerContextWrapper>& service_worker_context) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   BackgroundSyncManager* sync_manager =
       new BackgroundSyncManager(service_worker_context);
   sync_manager->Init();
   return make_scoped_ptr(sync_manager);
 }
 
 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);
 }
 
 BackgroundSyncManager::RegistrationKey::RegistrationKey(
     const BackgroundSyncRegistration& registration)
     : RegistrationKey(registration.options()->tag,
                       registration.options()->periodicity) {
 }
 
 BackgroundSyncManager::RegistrationKey::RegistrationKey(
@@ skipping 17 matching lines @@
   BackgroundSyncMetrics::RegistrationCouldFire registration_could_fire =
       AreOptionConditionsMet(options)
           ? BackgroundSyncMetrics::REGISTRATION_COULD_FIRE
           : BackgroundSyncMetrics::REGISTRATION_COULD_NOT_FIRE;
 
   if (disabled_) {
     BackgroundSyncMetrics::CountRegister(
         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;
   }
 
   op_scheduler_.ScheduleOperation(
       base::Bind(&BackgroundSyncManager::RegisterImpl,
                  weak_ptr_factory_.GetWeakPtr(), sw_registration_id, options,
                  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,
     SyncPeriodicity periodicity,
     const StatusAndRegistrationCallback& callback) {
   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;
   }
 
   RegistrationKey registration_key(sync_registration_tag, periodicity);
 
   op_scheduler_.ScheduleOperation(base::Bind(
       &BackgroundSyncManager::GetRegistrationImpl,
       weak_ptr_factory_.GetWeakPtr(), sw_registration_id, registration_key,
       MakeStatusAndRegistrationCompletion(callback)));
 }
 
 void BackgroundSyncManager::GetRegistrations(
     int64 sw_registration_id,
     SyncPeriodicity periodicity,
     const StatusAndRegistrationsCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   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;
   }
 
   op_scheduler_.ScheduleOperation(
       base::Bind(&BackgroundSyncManager::GetRegistrationsImpl,
                  weak_ptr_factory_.GetWeakPtr(), sw_registration_id,
                  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);
 
   // Operations already in the queue will either fail when they write to storage
   // or return stale results based on registrations loaded in memory. This is
   // inconsequential since the service worker is gone.
   op_scheduler_.ScheduleOperation(base::Bind(
       &BackgroundSyncManager::OnRegistrationDeletedImpl,
       weak_ptr_factory_.GetWeakPtr(), registration_id, MakeEmptyCompletion()));
@@ skipping 77 matching lines @@
         const BackgroundSyncRegistrationProto& registration_proto =
             registrations_proto.registration(i);
 
         if (registration_proto.id() >= registrations->next_id) {
           corruption_detected = true;
           break;
         }
 
         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();
         options->periodicity = registration_proto.periodicity();
         options->min_period = registration_proto.min_period();
         options->network_state = registration_proto.network_state();
         options->power_state = registration_proto.power_state();
 
         registration->set_id(registration_proto.id());
         registration->set_sync_state(registration_proto.sync_state());
@@ skipping 32 matching lines @@
   BackgroundSyncMetrics::RegistrationCouldFire registration_could_fire =
       AreOptionConditionsMet(options)
           ? BackgroundSyncMetrics::REGISTRATION_COULD_FIRE
           : BackgroundSyncMetrics::REGISTRATION_COULD_NOT_FIRE;
 
   if (disabled_) {
     BackgroundSyncMetrics::CountRegister(
         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;
   }
 
   ServiceWorkerRegistration* sw_registration =
       service_worker_context_->GetLiveRegistration(sw_registration_id);
   if (!sw_registration || !sw_registration->active_version()) {
     BackgroundSyncMetrics::CountRegister(
         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;
     }
 
     // Record the duplicated registration
     BackgroundSyncMetrics::CountRegister(
         existing_registration->options()->periodicity, registration_could_fire,
         BackgroundSyncMetrics::REGISTRATION_IS_DUPLICATE,
         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(
     const base::Closure& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   if (disabled_) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                   base::Bind(callback));
     return;
@@ skipping 37 matching lines @@
 void BackgroundSyncManager::DisableAndClearManagerClearedOne(
     const base::Closure& barrier_closure,
     ServiceWorkerStatusCode status) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   // The status doesn't matter at this point, there is nothing else to be done.
   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                 base::Bind(barrier_closure));
 }
 
-BackgroundSyncRegistration* BackgroundSyncManager::LookupRegistration(
+BackgroundSyncManager::RefCountedRegistration*
+BackgroundSyncManager::LookupRegistration(
     int64 sw_registration_id,
     const RegistrationKey& registration_key) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   SWIdToRegistrationsMap::iterator it =
       sw_to_registrations_map_.find(sw_registration_id);
   if (it == sw_to_registrations_map_.end())
     return nullptr;
 
   BackgroundSyncRegistrations& registrations = it->second;
   DCHECK_LE(BackgroundSyncRegistration::kInitialId, registrations.next_id);
   DCHECK(!registrations.origin.is_empty());
 
   auto key_and_registration_iter =
       registrations.registration_map.find(registration_key);
   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(
     int64 sw_registration_id,
     const ServiceWorkerStorage::StatusCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   // Serialize the data.
   const BackgroundSyncRegistrations& registrations =
       sw_to_registrations_map_[sw_registration_id];
   BackgroundSyncRegistrationsProto registrations_proto;
   registrations_proto.set_next_registration_id(registrations.next_id);
   registrations_proto.set_origin(registrations.origin.spec());
 
   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());
     registration_proto->set_sync_state(registration.sync_state());
     registration_proto->set_tag(registration.options()->tag);
     registration_proto->set_periodicity(registration.options()->periodicity);
     registration_proto->set_min_period(registration.options()->min_period);
     registration_proto->set_network_state(
         registration.options()->network_state);
     registration_proto->set_power_state(registration.options()->power_state);
   }
   std::string serialized;
   bool success = registrations_proto.SerializeToString(&serialized);
   DCHECK(success);
 
   StoreDataInBackend(sw_registration_id, registrations.origin,
                      kBackgroundSyncUserDataKey, serialized, callback);
 }
 
 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;
   }
 
   if (status != SERVICE_WORKER_OK) {
     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(
     int64 sw_registration_id,
     const RegistrationKey& registration_key) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(LookupRegistration(sw_registration_id, registration_key));
 
   BackgroundSyncRegistrations* registrations =
       &sw_to_registrations_map_[sw_registration_id];
 
   registrations->registration_map.erase(registration_key);
 }
 
 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;
 }
 
 void BackgroundSyncManager::StoreDataInBackend(
     int64 sw_registration_id,
     const GURL& origin,
     const std::string& backend_key,
     const std::string& data,
     const ServiceWorkerStorage::StatusCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   service_worker_context_->StoreRegistrationUserData(
       sw_registration_id, origin, backend_key, data, callback);
 }
 
 void BackgroundSyncManager::GetDataFromBackend(
     const std::string& backend_key,
     const ServiceWorkerStorage::GetUserDataForAllRegistrationsCallback&
         callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   service_worker_context_->GetUserDataForAllRegistrations(backend_key,
                                                           callback);
 }
 
 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::Unregister(
+    int64 sw_registration_id,
+    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,
-    const RegistrationKey& registration_key,
+    SyncPeriodicity periodicity,
     BackgroundSyncRegistration::RegistrationId sync_registration_id,
-    SyncPeriodicity periodicity,
     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;
   }
 
-  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(
         FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_NOT_FOUND));
     return;
   }
 
   RemoveRegistrationFromMap(sw_registration_id, registration_key);
 
   StoreRegistrations(sw_registration_id,
@@ skipping 33 matching lines @@
       FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_OK));
 }
 
 void BackgroundSyncManager::GetRegistrationImpl(
     int64 sw_registration_id,
     const RegistrationKey& registration_key,
     const StatusAndRegistrationCallback& callback) {
   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(
     int64 sw_registration_id,
     SyncPeriodicity periodicity,
     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;
   }
 
   SWIdToRegistrationsMap::iterator it =
       sw_to_registrations_map_.find(sw_registration_id);
 
   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(
     const BackgroundSyncRegistrationOptions& options) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   return network_observer_->NetworkSufficient(options.network_state) &&
          power_observer_->PowerSufficient(options.power_state);
 }
 
 bool BackgroundSyncManager::IsRegistrationReadyToFire(
@@ skipping 13 matching lines @@
 }
 
 void BackgroundSyncManager::SchedulePendingRegistrations() {
 #if defined(OS_ANDROID)
   bool keep_browser_alive_for_one_shot = false;
 
   for (const auto& sw_id_and_registrations : sw_to_registrations_map_) {
     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;
         } else {
           // TODO(jkarlin): Support keeping the browser alive for periodic
           // syncs.
         }
       }
     }
   }
@@ skipping 29 matching lines @@
     return;
   }
 
   // Find the registrations that are ready to run.
   std::vector<std::pair<int64, RegistrationKey>> sw_id_and_keys_to_fire;
 
   for (auto& sw_id_and_registrations : sw_to_registrations_map_) {
     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));
         // The state change is not saved to persistent storage because
         // if the sync event is killed mid-sync then it should return to
         // SYNC_STATE_PENDING.
         registration->set_sync_state(SYNC_STATE_FIRING);
       }
     }
   }
@@ skipping 12 matching lines @@
         sw_id_and_keys_to_fire.size(), base::Bind(callback));
 
     // Record the total time taken after all events have run to completion.
     base::Closure events_completed_barrier_closure =
         base::BarrierClosure(sw_id_and_keys_to_fire.size(),
                              base::Bind(&OnAllSyncEventsCompleted, start_time,
                                         sw_id_and_keys_to_fire.size()));
 
     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));
     }
   }
 
   SchedulePendingRegistrations();
 }
 
 void BackgroundSyncManager::FireReadyEventsDidFindRegistration(
     const RegistrationKey& registration_key,
     BackgroundSyncRegistration::RegistrationId registration_id,
     const base::Closure& event_fired_callback,
     const base::Closure& event_completed_callback,
     ServiceWorkerStatusCode service_worker_status,
     const scoped_refptr<ServiceWorkerRegistration>&
         service_worker_registration) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (service_worker_status != SERVICE_WORKER_OK) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(event_fired_callback));
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(event_completed_callback));
     return;
   }
 
-  BackgroundSyncRegistration* registration =
+  const RefCountedRegistration* registration =
       LookupRegistration(service_worker_registration->id(), registration_key);
+  DCHECK(registration);
 
   FireOneShotSync(
       *registration, service_worker_registration->active_version(),
       base::Bind(&BackgroundSyncManager::EventComplete,
                  weak_ptr_factory_.GetWeakPtr(), service_worker_registration,
                  service_worker_registration->id(), registration_key,
                  registration_id, event_completed_callback));
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(event_fired_callback));
@@ skipping 25 matching lines @@
     ServiceWorkerStatusCode status_code,
     const base::Closure& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   if (disabled_) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                   base::Bind(callback));
     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,
                                            status_code == SERVICE_WORKER_OK);
 
   if (registration->options()->periodicity == SYNC_ONE_SHOT) {
     if (status_code != SERVICE_WORKER_OK) {
       // TODO(jkarlin) Fire the sync event on the next page load controlled by
       // this registration. (crbug.com/479665)
       registration->set_sync_state(SYNC_STATE_FAILED);
@@ skipping 59 matching lines @@
 }
 
 void BackgroundSyncManager::OnStorageWipedImpl(const base::Closure& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   sw_to_registrations_map_.clear();
   disabled_ = false;
   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);
 
   FireReadyEvents();
 }
 
 void BackgroundSyncManager::OnPowerChanged() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   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) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   callback.Run(parameters...);
   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);
 
   return MakeClosureCompletion(base::Bind(base::DoNothing));
 }
 
 base::Closure BackgroundSyncManager::MakeClosureCompletion(
     const base::Closure& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   return base::Bind(
       &BackgroundSyncManager::CompleteOperationCallback<base::Closure>,
       weak_ptr_factory_.GetWeakPtr(), callback);
 }
 
 BackgroundSyncManager::StatusAndRegistrationCallback
 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
 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
 BackgroundSyncManager::MakeStatusCompletion(const StatusCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   return base::Bind(
       &BackgroundSyncManager::CompleteOperationCallback<StatusCallback,
                                                         BackgroundSyncStatus>,
       weak_ptr_factory_.GetWeakPtr(), callback);
 }
 
 }  // namespace content