Don't use the empty string as an url in MemoryCacheTest.

Source/core/fetch/MemoryCache.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
@@ skipping 91 matching lines @@
     if (!originalURL.protocolIsInHTTPFamily())
         return originalURL;
     KURL url = originalURL;
     url.removeFragmentIdentifier();
     return url;
 }
 
 void MemoryCache::add(Resource* resource)
 {
     ASSERT(WTF::isMainThread());
+    ASSERT(resource->url().isValid());
     RELEASE_ASSERT(!m_resources.contains(resource->url()));
-    m_resources.set(resource->url(), MemoryCacheEntry::create(resource));
+    m_resources.set(resource->url().string(), MemoryCacheEntry::create(resource));
     update(resource, 0, resource->size(), true);
 
     WTF_LOG(ResourceLoading, "MemoryCache::add Added '%s', resource %p\n", resource->url().string().latin1().data(), resource);
 }
 
 void MemoryCache::replace(Resource* newResource, Resource* oldResource)
 {
     if (MemoryCacheEntry* oldEntry = m_resources.get(oldResource->url()))
         evict(oldEntry);
     add(newResource);
@@ skipping 595 matching lines @@
                 printf("(%.1fK, %.1fK, %uA, %dR, %d, %d); ", current->decodedSize() / 1024.0f, (current->encodedSize() + current->overheadSize()) / 1024.0f, current->accessCount(), current->hasClients(), current->isPurgeable(), current->wasPurged());
 
             current = prev;
         }
     }
 }
 
 #endif // MEMORY_CACHE_STATS
 
 } // namespace WebCore