Cleanup: Remove unneeded forward declarations in webkit/.

webkit/quota/quota_database.h

 // Copyright (c) 2011 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 WEBKIT_QUOTA_QUOTA_DATABASE_H_
 #define WEBKIT_QUOTA_QUOTA_DATABASE_H_
 
 #include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "googleurl/src/gurl.h"
 #include "webkit/quota/quota_types.h"
 
 namespace sql {
 class Connection;
 class MetaTable;
-class Statement;
 }
 
 class GURL;
 
 namespace quota {
 
 class SpecialStoragePolicy;
 
 // All the methods of this class must run on the DB thread.
 class QuotaDatabase {
@@ skipping 142 matching lines @@
 
   static const TableSchema kTables[];
   static const IndexSchema kIndexes[];
 
   DISALLOW_COPY_AND_ASSIGN(QuotaDatabase);
 };
 
 }  // namespace quota
 
 #endif  // WEBKIT_QUOTA_QUOTA_DATABASE_H_