Use std::unique_ptr to transfer base::Value ownership in extensions::ValueStoreChange

chrome/browser/extensions/api/storage/syncable_settings_storage.cc

Index: chrome/browser/extensions/api/storage/syncable_settings_storage.cc
diff --git a/chrome/browser/extensions/api/storage/syncable_settings_storage.cc b/chrome/browser/extensions/api/storage/syncable_settings_storage.cc
index 543d2b443407195d772b22f3e98ea8753501cb6c..1626ff30e59c1de596bc59b8103e3d7f88967773 100644
--- a/chrome/browser/extensions/api/storage/syncable_settings_storage.cc
+++ b/chrome/browser/extensions/api/storage/syncable_settings_storage.cc
@@ -194,7 +194,7 @@ syncer::SyncError SyncableSettingsStorage::SendLocalSettingsToSync(
     std::string key = base::DictionaryValue::Iterator(*local_state).key();
     std::unique_ptr<base::Value> value;
     local_state->RemoveWithoutPathExpansion(key, &value);
-    changes.push_back(ValueStoreChange(key, nullptr, value.release()));
+    changes.push_back(ValueStoreChange(key, nullptr, std::move(value)));
   }
 
   syncer::SyncError error = sync_processor_->SendChanges(changes);
@@ -295,32 +295,32 @@ syncer::SyncError SyncableSettingsStorage::ProcessSyncChanges(
     switch ((*it)->change_type()) {
       case syncer::SyncChange::ACTION_ADD:
         if (!current_value.get()) {
-          error = OnSyncAdd(key, change_value.release(), &changes);
+          error = OnSyncAdd(key, std::move(change_value), &changes);
         } else {
           // Already a value; hopefully a local change has beaten sync in a
           // race and change's not a bug, so pretend change's an update.
           LOG(WARNING) << "Got add from sync for existing setting " <<
               extension_id_ << "/" << key;
-          error = OnSyncUpdate(key, current_value.release(),
-                               change_value.release(), &changes);
+          error = OnSyncUpdate(key, std::move(current_value),
+                               std::move(change_value), &changes);
         }
         break;
 
       case syncer::SyncChange::ACTION_UPDATE:
         if (current_value.get()) {
-          error = OnSyncUpdate(key, current_value.release(),
-                               change_value.release(), &changes);
+          error = OnSyncUpdate(key, std::move(current_value),
+                               std::move(change_value), &changes);
         } else {
           // Similarly, pretend change's an add.
           LOG(WARNING) << "Got update from sync for nonexistent setting" <<
               extension_id_ << "/" << key;
-          error = OnSyncAdd(key, change_value.release(), &changes);
+          error = OnSyncAdd(key, std::move(change_value), &changes);
         }
         break;
 
       case syncer::SyncChange::ACTION_DELETE:
         if (current_value.get()) {
-          error = OnSyncDelete(key, current_value.release(), &changes);
+          error = OnSyncDelete(key, std::move(current_value), &changes);
         } else {
           // Similarly, ignore change.
           LOG(WARNING) << "Got delete from sync for nonexistent setting " <<
@@ -349,7 +349,7 @@ syncer::SyncError SyncableSettingsStorage::ProcessSyncChanges(
 
 syncer::SyncError SyncableSettingsStorage::OnSyncAdd(
     const std::string& key,
-    base::Value* new_value,
+    std::unique_ptr<base::Value> new_value,
     ValueStoreChangeList* changes) {
   DCHECK(new_value);
   WriteResult result =
@@ -361,14 +361,14 @@ syncer::SyncError SyncableSettingsStorage::OnSyncAdd(
                            result->status().message.c_str()),
         sync_processor_->type());
   }
-  changes->push_back(ValueStoreChange(key, NULL, new_value));
+  changes->push_back(ValueStoreChange(key, nullptr, std::move(new_value)));
   return syncer::SyncError();
 }
 
 syncer::SyncError SyncableSettingsStorage::OnSyncUpdate(
     const std::string& key,
-    base::Value* old_value,
-    base::Value* new_value,
+    std::unique_ptr<base::Value> old_value,
+    std::unique_ptr<base::Value> new_value,
     ValueStoreChangeList* changes) {
   DCHECK(old_value);
   DCHECK(new_value);
@@ -381,13 +381,14 @@ syncer::SyncError SyncableSettingsStorage::OnSyncUpdate(
                            result->status().message.c_str()),
         sync_processor_->type());
   }
-  changes->push_back(ValueStoreChange(key, old_value, new_value));
+  changes->push_back(
+      ValueStoreChange(key, std::move(old_value), std::move(new_value)));
   return syncer::SyncError();
 }
 
 syncer::SyncError SyncableSettingsStorage::OnSyncDelete(
     const std::string& key,
-    base::Value* old_value,
+    std::unique_ptr<base::Value> old_value,
     ValueStoreChangeList* changes) {
   DCHECK(old_value);
   WriteResult result = HandleResult(delegate_->Remove(key));
@@ -398,7 +399,7 @@ syncer::SyncError SyncableSettingsStorage::OnSyncDelete(
                            result->status().message.c_str()),
         sync_processor_->type());
   }
-  changes->push_back(ValueStoreChange(key, old_value, NULL));
+  changes->push_back(ValueStoreChange(key, std::move(old_value), nullptr));
   return syncer::SyncError();
 }