Inform disk cache of WebKit memory cache hits.

net/disk_cache/entry_impl.h

Index: net/disk_cache/entry_impl.h
diff --git a/net/disk_cache/entry_impl.h b/net/disk_cache/entry_impl.h
index d54c3066ba7f22b50499160918b8394aed6cdd20..9911d8e1e3226ad5b70499e06d1b000876198c30 100644
--- a/net/disk_cache/entry_impl.h
+++ b/net/disk_cache/entry_impl.h
@@ -46,6 +46,7 @@ class NET_TEST EntryImpl : public Entry, public base::RefCounted<EntryImpl> {
   int GetAvailableRangeImpl(int64 offset, int len, int64* start);
   void CancelSparseIOImpl();
   int ReadyForSparseIOImpl(CompletionCallback* callback);
+  void UpdateRankForExternalCacheHitImpl();
 
   inline CacheEntryBlock* entry() {
     return &entry_;
@@ -148,6 +149,7 @@ class NET_TEST EntryImpl : public Entry, public base::RefCounted<EntryImpl> {
   virtual bool CouldBeSparse() const;
   virtual void CancelSparseIO();
   virtual int ReadyForSparseIO(net::CompletionCallback* completion_callback);
+  virtual void UpdateRankForExternalCacheHit();
 
  private:
   enum {