Remove void** from disk_cache interface.

net/disk_cache/memory/mem_backend_impl.cc

Index: net/disk_cache/memory/mem_backend_impl.cc
diff --git a/net/disk_cache/memory/mem_backend_impl.cc b/net/disk_cache/memory/mem_backend_impl.cc
index e69c00edf636a45379a7f29db182512dd8a67c36..7df8b2e8504cba779bfc9296572389904fa8fb8e 100644
--- a/net/disk_cache/memory/mem_backend_impl.cc
+++ b/net/disk_cache/memory/mem_backend_impl.cc
@@ -180,7 +180,7 @@ int MemBackendImpl::DoomEntriesSince(const base::Time initial_time,
   return net::ERR_FAILED;
 }
 
-int MemBackendImpl::OpenNextEntry(void** iter, Entry** next_entry,
+int MemBackendImpl::OpenNextEntry(Iterator* iter, Entry** next_entry,
                                   const CompletionCallback& callback) {
   if (OpenNextEntry(iter, next_entry))
     return net::OK;
@@ -188,10 +188,6 @@ int MemBackendImpl::OpenNextEntry(void** iter, Entry** next_entry,
   return net::ERR_FAILED;
 }
 
-void MemBackendImpl::EndEnumeration(void** iter) {
-  *iter = NULL;
-}
-
 void MemBackendImpl::OnExternalCacheHit(const std::string& key) {
   EntryMap::iterator it = entries_.find(key);
   if (it != entries_.end()) {
@@ -287,16 +283,29 @@ bool MemBackendImpl::DoomEntriesSince(const Time initial_time) {
   }
 }
 
-bool MemBackendImpl::OpenNextEntry(void** iter, Entry** next_entry) {
-  MemEntryImpl* current = reinterpret_cast<MemEntryImpl*>(*iter);
-  MemEntryImpl* node = rankings_.GetNext(current);
+bool MemBackendImpl::OpenNextEntry(Iterator* iter, Entry** next_entry) {
+  class State : public EnumerationState {
+   public:
+    State() : current_(NULL) {}
+
+    MemEntryImpl* current() { return current_; }
+    void set_current(MemEntryImpl* current) { current_ = current; }
+
+   private:
+    MemEntryImpl* current_;
+  };
+  if (!*iter)
+    iter->reset(new State());
+  State* state = static_cast<State*>(iter->get());
+
+  MemEntryImpl* node = rankings_.GetNext(state->current());
   // We should never return a child entry so iterate until we hit a parent
   // entry.
   while (node && node->type() != MemEntryImpl::kParentEntry) {
     node = rankings_.GetNext(node);
   }
   *next_entry = node;
-  *iter = node;
+  state->set_current(node);
 
   if (node)
     node->Open();