Reland of "Remove void** from disk_cache interface" w/ blockfile iter fix.

net/disk_cache/blockfile/in_flight_backend_io.h

Index: net/disk_cache/blockfile/in_flight_backend_io.h
diff --git a/net/disk_cache/blockfile/in_flight_backend_io.h b/net/disk_cache/blockfile/in_flight_backend_io.h
index 76557d16abccb71caaabdf9b41f7e463e5a50079..5d8e435953621b1e0c05dc4d1f2564ca4a564ee2 100644
--- a/net/disk_cache/blockfile/in_flight_backend_io.h
+++ b/net/disk_cache/blockfile/in_flight_backend_io.h
@@ -14,6 +14,7 @@
 #include "net/base/completion_callback.h"
 #include "net/base/io_buffer.h"
 #include "net/disk_cache/blockfile/in_flight_io.h"
+#include "net/disk_cache/blockfile/rankings.h"
 
 namespace disk_cache {
 
@@ -55,8 +56,8 @@ class BackendIO : public BackgroundIO {
   void DoomEntriesBetween(const base::Time initial_time,
                           const base::Time end_time);
   void DoomEntriesSince(const base::Time initial_time);
-  void OpenNextEntry(void** iter, Entry** next_entry);
-  void EndEnumeration(void* iterator);
+  void OpenNextEntry(Rankings::Iterator* iterator, Entry** next_entry);
+  void EndEnumeration(scoped_ptr<Rankings::Iterator> iterator);
   void OnExternalCacheHit(const std::string& key);
   void CloseEntryImpl(EntryImpl* entry);
   void DoomEntryImpl(EntryImpl* entry);
@@ -126,8 +127,8 @@ class BackendIO : public BackgroundIO {
   Entry** entry_ptr_;
   base::Time initial_time_;
   base::Time end_time_;
-  void** iter_ptr_;
-  void* iter_;
+  Rankings::Iterator* iterator_;
+  scoped_ptr<Rankings::Iterator> scoped_iterator_;
   EntryImpl* entry_;
   int index_;
   int offset_;
@@ -164,9 +165,9 @@ class InFlightBackendIO : public InFlightIO {
                           const net::CompletionCallback& callback);
   void DoomEntriesSince(const base::Time initial_time,
                         const net::CompletionCallback& callback);
-  void OpenNextEntry(void** iter, Entry** next_entry,
+  void OpenNextEntry(Rankings::Iterator* iterator, Entry** next_entry,
                      const net::CompletionCallback& callback);
-  void EndEnumeration(void* iterator);
+  void EndEnumeration(scoped_ptr<Rankings::Iterator> iterator);
   void OnExternalCacheHit(const std::string& key);
   void CloseEntryImpl(EntryImpl* entry);
   void DoomEntryImpl(EntryImpl* entry);