Update about:cache to display cached metadata for an entry....

net/http/http_cache.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file declares a HttpTransactionFactory implementation that can be
 // layered on top of another HttpTransactionFactory to add HTTP caching.  The
 // caching logic follows RFC 2616 (any exceptions are called out in the code).
 //
 // The HttpCache takes a disk_cache::Backend as a parameter, and uses that for
 // the cache storage.
@@ skipping 10 matching lines @@
 #include "base/file_path.h"
 #include "base/hash_tables.h"
 #include "base/scoped_ptr.h"
 #include "base/task.h"
 #include "base/weak_ptr.h"
 #include "net/base/cache_type.h"
 #include "net/base/completion_callback.h"
 #include "net/http/http_transaction_factory.h"
 
 class GURL;
+class ViewCacheHelper;
 
 namespace disk_cache {
 class Backend;
 class Entry;
 }
 
 namespace net {
 
 class HostResolver;
 class HttpAuthHandlerFactory;
@@ skipping 110 matching lines @@
 
   // Close currently active sockets so that fresh page loads will not use any
   // recycled connections.  For sockets currently in use, they may not close
   // immediately, but they will not be reusable. This is for debugging.
   void CloseCurrentConnections();
 
   void set_enable_range_support(bool value) {
     enable_range_support_ = value;
   }
 
+ protected:
+  // Disk cache entry data indices.
+  enum {
+    kResponseInfoIndex = 0,
+    kResponseContentIndex,
+    kMetadataIndex,
+
+    // Must remain at the end of the enum.
+    kNumCacheEntryDataIndices
+  };
+  friend class ::ViewCacheHelper;
+
  private:
 
   // Types --------------------------------------------------------------------
 
   class BackendCallback;
   class MetadataWriter;
   class Transaction;
   class WorkItem;
   friend class Transaction;
   struct NewEntry;  // Info for an entry under construction.
@@ skipping 148 matching lines @@
 
   typedef base::hash_map<std::string, int> PlaybackCacheMap;
   scoped_ptr<PlaybackCacheMap> playback_cache_map_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpCache);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_H_