Remove void** from disk_cache interface.

net/disk_cache/blockfile/backend_impl_v3.cc

Index: net/disk_cache/blockfile/backend_impl_v3.cc
diff --git a/net/disk_cache/blockfile/backend_impl_v3.cc b/net/disk_cache/blockfile/backend_impl_v3.cc
index 9a7cff1c79000c8e9e41f9f7728da3bf025cc680..bdc1cea630d178175ad275a37111b0f72714d7d2 100644
--- a/net/disk_cache/blockfile/backend_impl_v3.cc
+++ b/net/disk_cache/blockfile/backend_impl_v3.cc
@@ -660,17 +660,28 @@ int BackendImplV3::DoomEntriesSince(base::Time initial_time,
   }
 }
 
-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;
-}
+scoped_ptr<Backend::Iterator> BackendImplV3::CreateIterator() {
+  class BackendIterator : public Backend::Iterator {
+   public:
+    explicit BackendIterator(base::WeakPtr<InFlightBackendIO> background_queue)
+        : background_queue_(background_queue), data_(NULL) {}
+
+    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;
+    }
 
-void BackendImplV3::EndEnumeration(void** iter) {
-  scoped_ptr<IndexIterator> iterator(
-      reinterpret_cast<IndexIterator*>(*iter));
-  *iter = NULL;
+   private:
+    const base::WeakPtr<InFlightBackendIO> background_queue_;
+    void* data_;
+  };
+
+  return
+      scoped_ptr<Backend::Iterator>(new BackendIterator(GetBackgroundQueue()));
 }
 
 void BackendImplV3::GetStats(StatsItems* stats) {
@@ -1497,13 +1508,16 @@ int BackendImplV3::DoomEntriesSince(base::Time initial_time,
   return net::ERR_FAILED;
 }
 
-int BackendImplV3::OpenNextEntry(void** iter, Entry** next_entry,
-                                 const CompletionCallback& callback) {
-  return net::ERR_FAILED;
-}
-
-void BackendImplV3::EndEnumeration(void** iter) {
-  NOTIMPLEMENTED();
+scoped_ptr<Backend::Iterator> BackendImplV3::CreateIterator() {
+  class NotImplementedIterator : public Iterator {
+   public:
+    virtual int OpenNextEntry(
+        disk_cache::Entry** next_entry,
+        const net::CompletionCallback& callback) OVERRIDE {
+      return net::ERR_NOT_IMPLEMENTED;
+    }
+  };
+  return scoped_ptr<Iterator>(new NotImplementedIterator());
 }
 
 void BackendImplV3::GetStats(StatsItems* stats) {