Revert of Remove void** from disk_cache interface.

net/tools/dump_cache/simple_cache_dumper.h

Index: net/tools/dump_cache/simple_cache_dumper.h
diff --git a/net/tools/dump_cache/simple_cache_dumper.h b/net/tools/dump_cache/simple_cache_dumper.h
index cc865a34b26c4723ea4d5fddc78fe9989091f065..c95e6a961689eab909aaea0a4414c491c14c3c5a 100644
--- a/net/tools/dump_cache/simple_cache_dumper.h
+++ b/net/tools/dump_cache/simple_cache_dumper.h
@@ -9,9 +9,13 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/thread.h"
 #include "net/base/completion_callback.h"
-#include "net/disk_cache/disk_cache.h"
 
 class DiskDumper;
+
+namespace disk_cache {
+class Backend;
+class Entry;
+}  // namespace disk_cache
 
 namespace net {
 
@@ -75,7 +79,7 @@
   scoped_ptr<disk_cache::Backend> cache_;
   scoped_ptr<DiskDumper> writer_;
   base::Thread* cache_thread_;
-  scoped_ptr<disk_cache::Backend::Iterator> iter_;
+  void* iter_;
   disk_cache::Entry* src_entry_;
   disk_cache::Entry* dst_entry_;
   CompletionCallback io_callback_;