Remove unused blink::WebStorageArea::memoryBytesUsedByCache().

third_party/WebKit/public/platform/WebStorageArea.h

 /*
  * Copyright (C) 2009 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 67 matching lines @@
         removeItem(key, pageUrl, unused);
     }
 
     // Clear all key/value pairs. |pageUrl| is the url that should be used if a storage event fires.
     virtual void clear(const WebURL& pageUrl)
     {
         bool unused;
         clear(pageUrl, unused);
     }
 
-    // Returns amount of bytes occupied by the storage cache in physical memory.
-    virtual size_t memoryBytesUsedByCache() const { return 0; }
-
     // DEPRECATED - being replaced by the async variants above which do not return oldValues or block until completion.
     virtual void setItem(const WebString& key, const WebString& newValue, const WebURL&, Result&, WebString& oldValue) { }
     virtual void removeItem(const WebString& key, const WebURL& pageUrl, WebString& oldValue)  { }
     virtual void clear(const WebURL& pageUrl, bool& somethingCleared)  { }
 };
 
 } // namespace blink
 
 #endif // WebStorageArea_h