[IndexedDB] Pool and evict leveldb iterators, to save memory

content/browser/indexed_db/indexed_db_class_factory.cc

Index: content/browser/indexed_db/indexed_db_class_factory.cc
diff --git a/content/browser/indexed_db/indexed_db_class_factory.cc b/content/browser/indexed_db/indexed_db_class_factory.cc
index c6e2489ed1f802f4cc9d9f2b6ade7e87dd4ef2c7..83f92a220f43a0db146077dc67cc4d4536a754c6 100644
--- a/content/browser/indexed_db/indexed_db_class_factory.cc
+++ b/content/browser/indexed_db/indexed_db_class_factory.cc
@@ -54,8 +54,11 @@ IndexedDBClassFactory::CreateLevelDBTransaction(LevelDBDatabase* db) {
 }
 
 std::unique_ptr<LevelDBIteratorImpl> IndexedDBClassFactory::CreateIteratorImpl(
-    std::unique_ptr<leveldb::Iterator> iterator) {
-  return base::WrapUnique(new LevelDBIteratorImpl(std::move(iterator)));
+    std::unique_ptr<leveldb::Iterator> iterator,
+    LevelDBDatabase* db,
+    const leveldb::Snapshot* snapshot) {
+  return base::WrapUnique(
+      new LevelDBIteratorImpl(std::move(iterator), db, snapshot));
 }
 
 }  // namespace content