Remove void** from disk_cache interface.

net/disk_cache/blockfile/backend_impl.cc

 // Copyright (c) 2012 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.
 
 #include "net/disk_cache/blockfile/backend_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
@@ skipping 1232 matching lines @@
   return net::ERR_IO_PENDING;
 }
 
 int BackendImpl::DoomEntriesSince(const base::Time initial_time,
                                   const CompletionCallback& callback) {
   DCHECK(!callback.is_null());
   background_queue_.DoomEntriesSince(initial_time, callback);
   return net::ERR_IO_PENDING;
 }
 
-int BackendImpl::OpenNextEntry(void** iter, Entry** next_entry,
+int BackendImpl::OpenNextEntry(Iterator* iter, Entry** next_entry,
                                const CompletionCallback& callback) {
+  // TODO(gavinp): Remove all void** iter from cache.
   DCHECK(!callback.is_null());
-  background_queue_.OpenNextEntry(iter, next_entry, callback);
+
+  class State : public EnumerationState {
+   public:
+    explicit State(base::WeakPtr<InFlightBackendIO> background_queue)
+        : background_queue_(background_queue),
+        data_(NULL) {}
+
+    virtual ~State() {
+      if (background_queue_)
+        background_queue_->EndEnumeration(*data());
+    }
+
+    void** data() { return &data_; }
+
+   private:
+    base::WeakPtr<InFlightBackendIO> background_queue_;
+    void* data_;
+  };
+
+  if (!*iter)
+    iter->reset(new State(GetBackgroundQueue()));
+  State* state = static_cast<State*>(iter->get());
+
+  background_queue_.OpenNextEntry(state->data(), next_entry, callback);
   return net::ERR_IO_PENDING;
 }
 
-void BackendImpl::EndEnumeration(void** iter) {
-  background_queue_.EndEnumeration(*iter);
-  *iter = NULL;
-}
-
 void BackendImpl::GetStats(StatsItems* stats) {
   if (disabled_)
     return;
 
   std::pair<std::string, std::string> item;
 
   item.first = "Entries";
   item.second = base::StringPrintf("%d", data_->header.num_entries);
   stats->push_back(item);
 
@@ skipping 791 matching lines @@
     if (total_memory > kMaxBuffersSize || total_memory <= 0)
       total_memory = kMaxBuffersSize;
 
     done = true;
   }
 
   return static_cast<int>(total_memory);
 }
 
 }  // namespace disk_cache