IndexedDB: Remove prefetching method stubs from Blink

Source/WebKit/chromium/src/IDBCursorBackendProxy.h

 /*
  * Copyright (C) 2011 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 24 matching lines @@
 
 namespace WebKit {
 
 class IDBCursorBackendProxy : public WebCore::IDBCursorBackendInterface {
 public:
     static PassRefPtr<WebCore::IDBCursorBackendInterface> create(PassOwnPtr<WebIDBCursor>);
     virtual ~IDBCursorBackendProxy();
 
     virtual void advance(unsigned long, PassRefPtr<WebCore::IDBCallbacks>);
     virtual void continueFunction(PassRefPtr<WebCore::IDBKey>, PassRefPtr<WebCore::IDBCallbacks>);
-    virtual void prefetchContinue(int numberToFetch, PassRefPtr<WebCore::IDBCallbacks>) { ASSERT_NOT_REACHED(); } // Only used in the backend.
-    virtual void prefetchReset(int usedPrefetches, int unusedPrefetches) { ASSERT_NOT_REACHED(); } // Only used in the backend.
     virtual void postSuccessHandlerCallback();
 
 private:
     IDBCursorBackendProxy(PassOwnPtr<WebIDBCursor>);
 
     OwnPtr<WebIDBCursor> m_idbCursor;
 };
 
 } // namespace WebKit
 
 #endif // IDBCursorBackendProxy_h