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

content/browser/indexed_db/indexed_db_backing_store.h

 // Copyright (c) 2013 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.
 
 #ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_BACKING_STORE_H_
 #define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_BACKING_STORE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 466 matching lines @@
       int64_t object_store_id) WARN_UNUSED_RESULT;
   virtual leveldb::Status DeleteRecord(
       IndexedDBBackingStore::Transaction* transaction,
       int64_t database_id,
       int64_t object_store_id,
       const RecordIdentifier& record) WARN_UNUSED_RESULT;
   virtual leveldb::Status DeleteRange(
       IndexedDBBackingStore::Transaction* transaction,
       int64_t database_id,
       int64_t object_store_id,
-      const IndexedDBKeyRange&,
-      size_t* delete_count) WARN_UNUSED_RESULT;
+      const IndexedDBKeyRange&) WARN_UNUSED_RESULT;
   virtual leveldb::Status GetKeyGeneratorCurrentNumber(
       IndexedDBBackingStore::Transaction* transaction,
       int64_t database_id,
       int64_t object_store_id,
       int64_t* current_number) WARN_UNUSED_RESULT;
   virtual leveldb::Status MaybeUpdateKeyGeneratorCurrentNumber(
       IndexedDBBackingStore::Transaction* transaction,
       int64_t database_id,
       int64_t object_store_id,
       int64_t new_state,
@@ skipping 195 matching lines @@
   // complete. While > 0, temporary journal entries may exist so out-of-band
   // journal cleaning must be deferred.
   size_t committing_transaction_count_;
 
   DISALLOW_COPY_AND_ASSIGN(IndexedDBBackingStore);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_BACKING_STORE_H_