IndexedDB: Remove prefetching method stubs from Blink

Source/modules/indexeddb/IDBCursorBackendInterface.h

 /*
  * Copyright (C) 2010 Google 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
@@ skipping 25 matching lines @@
 class IDBRequest;
 
 typedef int ExceptionCode;
 
 class IDBCursorBackendInterface : public RefCounted<IDBCursorBackendInterface> {
 public:
     virtual ~IDBCursorBackendInterface() {}
 
     virtual void advance(unsigned long count, PassRefPtr<IDBCallbacks>) = 0;
     virtual void continueFunction(PassRefPtr<IDBKey> key, PassRefPtr<IDBCallbacks>) = 0;
-    virtual void prefetchContinue(int numberToFetch, PassRefPtr<IDBCallbacks>) = 0;
-    virtual void prefetchReset(int usedPrefetches, int unusedPrefetches) = 0;
     virtual void postSuccessHandlerCallback() = 0;
 };
 
 } // namespace WebCore
 
 #endif // IDBCursorBackendInterface_h