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 {
 const char kBackgroundSyncUserDataKey[] = "BackgroundSyncUserData";
@@ skipping 17 matching lines @@
 
   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());

[iclelland, 2015/08/14 14:44:18]

What happens if a renderer crashed (for unrelated reasons), while still holding
on to a reference to a ClientBackgroundSyncRegistration, at some time before the
manager is deleted? Will this code escalate that to a full browser crash?

[jkarlin, 2015/08/17 17:14:49]

The BackgroundSyncServiceImpl tracks all of the references that the renderer
has. If the renderer crashes its mojo pipe will die and the
BackgroundSyncServiceImpl will die, releasing the references.

[iclelland, 2015/08/17 19:22:02]

That seems sound, thanks.

+
   service_worker_context_->RemoveObserver(this);
 }
 
 BackgroundSyncManager::RegistrationKey::RegistrationKey(
     const BackgroundSyncRegistration& registration)
     : RegistrationKey(registration.options()->tag,
                       registration.options()->periodicity) {
 }
 
 BackgroundSyncManager::RegistrationKey::RegistrationKey(
@@ skipping 18 matching lines @@
       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()));
+        FROM_HERE,
+        base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
+                   base::Passed(
+                       scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));

[iclelland, 2015/08/14 14:44:18]

This change is repeated so many times in this file -- would it makes sense to
have a function to encapsulate the entire PostTask call for storage errors?

[jkarlin, 2015/08/17 17:14:49]

Good idea. Done.

     return;
   }
 
   op_scheduler_.ScheduleOperation(
       base::Bind(&BackgroundSyncManager::RegisterImpl,
                  weak_ptr_factory_.GetWeakPtr(), sw_registration_id, options,
                  MakeStatusAndRegistrationCompletion(callback)));
 }
 
 void BackgroundSyncManager::Unregister(

[iclelland, 2015/08/14 14:44:18]

This method was made private in the header file; does it need to be moved
elsewhere in the .cc file to match?

[jkarlin, 2015/08/17 17:18:15]

Done.

     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,
+      sw_registration_id, periodicity, sync_registration_id,
       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()));
+        FROM_HERE,
+        base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
+                   base::Passed(
+                       scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
     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)));
 }
 
+void BackgroundSyncManager::ReleaseRegistration(
+    BackgroundSyncRegistration::RegistrationId sync_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (!client_registration_ids_.Lookup(sync_id)) {
+    // TODO(jkarlin): Abort the render process.

[iclelland, 2015/08/14 14:44:18]

What happens right now (by not aborting?) Is anything left in an inconsistent
state, or will the renderer clean itself up once it believes that the
registration has been released?

[jkarlin, 2015/08/17 17:14:49]

I made some changes to BackgroundSyncServiceImpl::TrackRegistration so that this
can be a DCHECK instead. Done.

+    LOG(ERROR) << "Client attempted to release a non-existant registration";
+    return;
+  }
+  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 33 matching lines @@
       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()));
+        FROM_HERE,
+        base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
+                   base::Passed(
+                       scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
     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()));
+                   base::Passed(
+                       scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
     return;
   }
 
   if (!sw_registration->active_version()->HasWindowClients()) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_NOT_ALLOWED,
-                              BackgroundSyncRegistration()));
+        FROM_HERE,
+        base::Bind(callback, BACKGROUND_SYNC_STATUS_NOT_ALLOWED,
+                   base::Passed(
+                       scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
     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()));
+        FROM_HERE,
+        base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
+                   base::Passed(
+                       scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
     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.get()).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,
+    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 might will hold the reference until it is destroyed.

[iclelland, 2015/08/14 14:44:18]

"might will"

[jkarlin, 2015/08/17 17:14:49]

Done.

+  // The ~BackgroundSyncManager DCHECKS verify that this is uncommon.
+  SyncRegistrationPtr sync_registration =
+      mojo::ConvertTo<SyncRegistrationPtr>(*registration->value());
+  scoped_refptr<RefCountedRegistration>* ptr =
+      new scoped_refptr<RefCountedRegistration>(registration);
+  sync_registration->id = client_registration_ids_.Add(ptr);
+
+  active_version->DispatchSyncEvent(sync_registration.Pass(), 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<RefCountedRegistration>* hosted_registration_ref =
+      client_registration_ids_.Lookup(sync_registration_id);
+
+  if (!hosted_registration_ref) {
+    LOG(ERROR) << "Client attempted to access a nonexistent registration";
+    BackgroundSyncMetrics::CountUnregister(periodicity,
+                                           BACKGROUND_SYNC_STATUS_NOT_ALLOWED);
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_NOT_ALLOWED));
+    return;
+  }
+
+  BackgroundSyncRegistration* hosted_registration =
+      (*hosted_registration_ref)->value();
+
+  RegistrationKey registration_key(hosted_registration->options()->tag,
+                                   periodicity);
+  RefCountedRegistration* existing_registration =

[iclelland, 2015/08/14 14:44:18]

const removed?

[jkarlin, 2015/08/17 17:14:49]

Done.

       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 34 matching lines @@
 }
 
 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()));
+        FROM_HERE,
+        base::Bind(callback, BACKGROUND_SYNC_STATUS_STORAGE_ERROR,
+                   base::Passed(
+                       scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
     return;
   }
 
-  const BackgroundSyncRegistration* out_registration =
+  RefCountedRegistration* registration =

[iclelland, 2015/08/14 14:44:18]

const removed?

Actually there are a lot of these here -- is there an issue with RefCounted
objects not being const'able? You've defined an explicit const value() method,
so I didn't think so, but it's been pretty consistently removed in this file.

[jkarlin, 2015/08/17 17:14:49]

Thanks, I've added const where possible.

       LookupRegistration(sw_registration_id, registration_key);
-  if (!out_registration) {
+  if (!registration) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
-        FROM_HERE, base::Bind(callback, BACKGROUND_SYNC_STATUS_NOT_FOUND,
-                              BackgroundSyncRegistration()));
+        FROM_HERE,
+        base::Bind(callback, BACKGROUND_SYNC_STATUS_NOT_FOUND,
+                   base::Passed(
+                       scoped_ptr<ClientBackgroundSyncRegistration>().Pass())));
     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);
+      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 =
+      RefCountedRegistration* registration =
           LookupRegistration(service_worker_id, sw_id_and_key.second);
 
       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 =
+  RefCountedRegistration* registration =
       LookupRegistration(service_worker_registration->id(), registration_key);
 
   FireOneShotSync(
-      *registration, service_worker_registration->active_version(),
+      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));
 }
 
 // |service_worker_registration| is just to keep the registration alive
@@ skipping 22 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(
+    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<RefCountedRegistration>* ptr =
+      new scoped_refptr<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();
 }
 
 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(

[iclelland, 2015/08/14 14:44:18]

Why are these two functions specified? I don't see why they're not just
instantiations of the CompleteOperationCallback anymore

[jkarlin, 2015/08/17 17:14:49]

Because they're passing scoped_ptrs that need to be passed. There is some magic
template way to do it (that's how bind works with base::Passed etc.) but I don't
know what it is. Added TODO though.

[iclelland, 2015/08/17 19:22:02]

That makes sense -- thanks for the explanation. I'm sure you're right, that
there is some template magic that would fix it, and that it's probably fine to
not spend any time on it right now.

+    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