Disk cache: Remove remaining uses of RankingsNode.pointer....

net/disk_cache/disk_format.h

 // Copyright (c) 2006-2009 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.
 
 // The cache is stored on disk as a collection of block-files, plus an index
 // file plus a collection of external files.
 //
 // Any data blob bigger than kMaxBlockSize (net/addr.h) will be stored on a
 // separate file named f_xxx where x is a hexadecimal number. Shorter data will
 // be stored as a series of blocks on a block-file. In any case, CacheAddr
@@ skipping 136 matching lines @@
 
 #pragma pack(push, 4)
 // Rankings information for a given entry.
 struct RankingsNode {
   uint64      last_used;        // LRU info.
   uint64      last_modified;    // LRU info.
   CacheAddr   next;             // LRU list.
   CacheAddr   prev;             // LRU list.
   CacheAddr   contents;         // Address of the EntryStore.
   int32       dirty;            // The entry is being modifyied.
-  void*       pointer;          // Pointer to the in-memory entry.
+  int32       dummy;            // Old files may have a pointer here.
 };
 #pragma pack(pop)
 
 COMPILE_ASSERT(sizeof(RankingsNode) == 36, bad_RankingsNode);
 
 const uint32 kBlockMagic = 0xC104CAC3;
 const int kBlockHeaderSize = 8192;  // Two pages: almost 64k entries
 const int kMaxBlocks = (kBlockHeaderSize - 80) * 8;
 
 // Bitmap to track used blocks on a block-file.
@@ skipping 89 matching lines @@
 };
 
 // The number of blocks stored by a child entry.
 const int kNumSparseBits = 1024;
 COMPILE_ASSERT(sizeof(SparseData) == sizeof(SparseHeader) + kNumSparseBits / 8,
                Invalid_SparseData_bitmap);
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_DISK_FORMAT_H_