Disk cache: Add base files for implementation of file format version 3.

net/disk_cache/v3/eviction_v3.h

Index: net/disk_cache/v3/eviction_v3.h
===================================================================
--- net/disk_cache/v3/eviction_v3.h	(revision 0)
+++ net/disk_cache/v3/eviction_v3.h	(working copy)
@@ -30,14 +30,9 @@
   // use.
   void TrimCache(bool empty);
 
-  // Updates the ranking information for an entry.
-  void UpdateRank(EntryImpl* entry, bool modified);
-
   // Notifications of interesting events for a given entry.
   void OnOpenEntry(EntryImpl* entry);
   void OnCreateEntry(EntryImpl* entry);
-  void OnDoomEntry(EntryImpl* entry);
-  void OnDestroyEntry(EntryImpl* entry);
 
   // Testing interface.
   void SetTestMode();
@@ -48,22 +43,10 @@
   void DelayedTrim();
   bool ShouldTrim();
   bool ShouldTrimDeleted();
-  void ReportTrimTimes(EntryImpl* entry);
-  Rankings::List GetListForEntry(EntryImpl* entry);
   bool EvictEntry(CacheRankingsBlock* node, bool empty, Rankings::List list);
 
-  // We'll just keep for a while a separate set of methods that implement the
-  // new eviction algorithm. This code will replace the original methods when
-  // finished.
   void TrimCacheV2(bool empty);
-  void UpdateRankV2(EntryImpl* entry, bool modified);
-  void OnOpenEntryV2(EntryImpl* entry);
-  void OnCreateEntryV2(EntryImpl* entry);
-  void OnDoomEntryV2(EntryImpl* entry);
-  void OnDestroyEntryV2(EntryImpl* entry);
-  Rankings::List GetListForEntryV2(EntryImpl* entry);
   void TrimDeleted(bool empty);
-  bool RemoveDeletedNode(CacheRankingsBlock* node);
 
   bool NodeIsOldEnough(CacheRankingsBlock* node, int list);
   int SelectListByLength(Rankings::ScopedRankingsBlock* next);