Revert of Remove void** from disk_cache interface.

net/disk_cache/blockfile/backend_impl_v3.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_v3.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
@@ skipping 642 matching lines @@
       SyncEndEnumeration(iter);
       return net::OK;
     }
 
     entry->DoomImpl();
     entry->Release();
     SyncEndEnumeration(iter);  // Dooming the entry invalidates the iterator.
   }
 }
 
-class BackendImplV3::IteratorImpl : public Backend::Iterator {
- public:
-  explicit IteratorImpl(base::WeakPtr<InFlightBackendIO> background_queue)
-      : background_queue_(background_queue), data_(NULL) {
-  }
+int BackendImplV3::OpenNextEntry(void** iter, Entry** next_entry,
+                                 const CompletionCallback& callback) {
+  DCHECK(!callback.is_null());
+  background_queue_.OpenNextEntry(iter, next_entry, callback);
+  return net::ERR_IO_PENDING;
+}
 
-  virtual int OpenNextEntry(Entry** next_entry,
-                            const net::CompletionCallback& callback) OVERRIDE {
-    if (!background_queue_)
-      return net::ERR_FAILED;
-    background_queue_->OpenNextEntry(&data_, next_entry, callback);
-    return net::ERR_IO_PENDING;
-  }
-
- private:
-  const base::WeakPtr<InFlightBackendIO> background_queue_;
-  void* data_;
-};
-
-scoped_ptr<Backend::Iterator> BackendImplV3::CreateIterator() {
-  return scoped_ptr<Backend::Iterator>(new IteratorImpl(GetBackgroundQueue()));
+void BackendImplV3::EndEnumeration(void** iter) {
+  scoped_ptr<IndexIterator> iterator(
+      reinterpret_cast<IndexIterator*>(*iter));
+  *iter = NULL;
 }
 
 void BackendImplV3::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);
@@ skipping 806 matching lines @@
                                       base::Time end_time,
                                       const CompletionCallback& callback) {
   return net::ERR_FAILED;
 }
 
 int BackendImplV3::DoomEntriesSince(base::Time initial_time,
                                     const CompletionCallback& callback) {
   return net::ERR_FAILED;
 }
 
+int BackendImplV3::OpenNextEntry(void** iter, Entry** next_entry,
+                                 const CompletionCallback& callback) {
+  return net::ERR_FAILED;
+}
 
-class BackendImplV3::NotImplementedIterator : public Backend::Iterator {
- public:
-  virtual int OpenNextEntry(disk_cache::Entry** next_entry,
-                            const net::CompletionCallback& callback) OVERRIDE {
-    return net::ERR_NOT_IMPLEMENTED;
-  }
-};
-
-scoped_ptr<Backend::Iterator> BackendImplV3::CreateIterator() {
-  return scoped_ptr<Iterator>(new NotImplementedIterator());
+void BackendImplV3::EndEnumeration(void** iter) {
+  NOTIMPLEMENTED();
 }
 
 void BackendImplV3::GetStats(StatsItems* stats) {
   NOTIMPLEMENTED();
 }
 
 void BackendImplV3::OnExternalCacheHit(const std::string& key) {
   NOTIMPLEMENTED();
 }
 
 void BackendImplV3::CleanupCache() {
 }
 
 }  // namespace disk_cache