Inform disk cache of WebKit memory cache hits.

net/disk_cache/disk_cache.h

Index: net/disk_cache/disk_cache.h
diff --git a/net/disk_cache/disk_cache.h b/net/disk_cache/disk_cache.h
index 973b6e61a507b1be1d97707eb744ef8a33dc2366..7e714e66e7df91b66766ed5b906b522833322296 100644
--- a/net/disk_cache/disk_cache.h
+++ b/net/disk_cache/disk_cache.h
@@ -291,6 +291,11 @@ class NET_TEST Entry {
   // Note: This method is deprecated.
   virtual int ReadyForSparseIO(CompletionCallback* completion_callback) = 0;
 
+  // Improves the rank of this entry in the LRU cache as if it had been used
+  // directly. This allows feedback from the renderer's memory cache to improve

[rvargas (doing something else), 2011/07/27 23:26:17]

net is not aware of what a renderer is. I think that the name of this method is
a bit too specific... it implies that the caller knows what a "rank" is, and the
comments talks about LRU...

Maybe something closer to OnExternalCacheHit(), OnEntryReused(),
EntryReused()...

Also, this should be a member of the backend and not the entry: if the user has
an open entry there is little to do, and if it has to open the entry that should
do the trick by itself. (note that making this change implies that my previous
comment about the location of the test is no longer valid)

+  // the selection of resources in the disk cache.
+  virtual void UpdateRankForExternalCacheHit() = 0;
+
  protected:
   virtual ~Entry() {}
 };