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

content/browser/indexed_db/indexed_db_database.cc

 // 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.
 
 #include "content/browser/indexed_db/indexed_db_database.h"
 
 #include <math.h>
 
 #include <limits>
 #include <set>
@@ skipping 1661 matching lines @@
                                        callbacks));
 }
 
 leveldb::Status IndexedDBDatabase::DeleteRangeOperation(
     int64_t object_store_id,
     std::unique_ptr<IndexedDBKeyRange> key_range,
     scoped_refptr<IndexedDBCallbacks> callbacks,
     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();
   FilterObservation(transaction, object_store_id, blink::WebIDBDelete,
                     *key_range, nullptr);
   return s;
 }
 
 void IndexedDBDatabase::Clear(IndexedDBTransaction* transaction,
                               int64_t object_store_id,
@@ skipping 253 matching lines @@
   if (status.IsCorruption()) {
     IndexedDBDatabaseError error(blink::WebIDBDatabaseExceptionUnknownError,
                                  message);
     factory_->HandleBackingStoreCorruption(backing_store_->origin(), error);
   } else {
     factory_->HandleBackingStoreFailure(backing_store_->origin());
   }
 }
 
 }  // namespace content