IndexedDB: Remove prefetching method stubs from Blink

public/platform/WebIDBCursor.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 29 matching lines @@
 
     enum Direction {
         Next = 0,
         NextNoDuplicate = 1,
         Prev = 2,
         PrevNoDuplicate = 3,
     };
 
     virtual void advance(unsigned long, WebIDBCallbacks*) { WEBKIT_ASSERT_NOT_REACHED(); }
     virtual void continueFunction(const WebIDBKey&, WebIDBCallbacks*) { WEBKIT_ASSERT_NOT_REACHED(); }
-    virtual void prefetchContinue(int numberToFetch, WebIDBCallbacks*) { WEBKIT_ASSERT_NOT_REACHED(); }
-    virtual void prefetchReset(int usedPrefetches, int unusedPrefetches) { WEBKIT_ASSERT_NOT_REACHED(); }
     virtual void postSuccessHandlerCallback() { } // Only used in frontend.
 
 protected:
     WebIDBCursor() { }
 };
 
 } // namespace WebKit
 
 #endif // WebIDBCursor_h