Clean up forward declarations in Source/modules

Source/modules/webdatabase/Database.h

 /*
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 21 matching lines @@
 #include "modules/webdatabase/sqlite/SQLiteDatabase.h"
 #include "platform/weborigin/SecurityOrigin.h"
 #include "wtf/Deque.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class ChangeVersionData;
 class DatabaseAuthorizer;
 class DatabaseContext;
-class DatabaseServer;
 class ExecutionContext;
 class SQLTransaction;
 class SQLTransactionBackend;
 class SQLTransactionCallback;
 class SQLTransactionClient;
 class SQLTransactionCoordinator;
 class SQLTransactionErrorCallback;
 class VoidCallback;
 
 class Database final : public GarbageCollectedFinalized<Database>, public ScriptWrappable {
@@ skipping 124 matching lines @@
     friend class ChangeVersionWrapper;
     friend class DatabaseManager;
     friend class SQLStatementBackend;
     friend class SQLTransaction;
     friend class SQLTransactionBackend;
 };
 
 } // namespace blink
 
 #endif // Database_h