Fix MEMORY_CACHE_STATS compilation.
Fix MEMORY_CACHE_STATS compilation.

Update MemoryCache::dumpLRULists() to work over the current representation
of MemoryCacheEntry and its attached resource.

This debug-only method wasn't updated as part of https://codereview.chromium.org/174523002 (r168851.)

R=dcheng,mkwst
BUG=

Review URL: https://codereview.chromium.org/758673002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@186017 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs