IndexedDB: Optimize range deletion operations (e.g. clearing a store)

content/browser/indexed_db/indexed_db_database.cc

Index: content/browser/indexed_db/indexed_db_database.cc
diff --git a/content/browser/indexed_db/indexed_db_database.cc b/content/browser/indexed_db/indexed_db_database.cc
index 239222981f051bdf405c00b47895af89dfa7e8cd..ca13e95dbc151c70c4cee6a548773d9e4f02b851 100644
--- a/content/browser/indexed_db/indexed_db_database.cc
+++ b/content/browser/indexed_db/indexed_db_database.cc
@@ -1679,10 +1679,9 @@ leveldb::Status IndexedDBDatabase::DeleteRangeOperation(
     IndexedDBTransaction* transaction) {
   IDB_TRACE1("IndexedDBDatabase::DeleteRangeOperation", "txn.id",
              transaction->id());
-  size_t delete_count = 0;
   leveldb::Status s =
       backing_store_->DeleteRange(transaction->BackingStoreTransaction(), id(),
-                                  object_store_id, *key_range, &delete_count);
+                                  object_store_id, *key_range);
   if (!s.ok())
     return s;
   callbacks->OnSuccess();