Revert of 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 848ef985db9c4621711dd9ce47cba396445286fa..e69c00edf636a45379a7f29db182512dd8a67c36 100644
--- a/net/disk_cache/memory/mem_backend_impl.cc
+++ b/net/disk_cache/memory/mem_backend_impl.cc
@@ -29,8 +29,7 @@
 namespace disk_cache {
 
 MemBackendImpl::MemBackendImpl(net::NetLog* net_log)
-    : max_size_(0), current_size_(0), net_log_(net_log), weak_factory_(this) {
-}
+    : max_size_(0), current_size_(0), net_log_(net_log) {}
 
 MemBackendImpl::~MemBackendImpl() {
   EntryMap::iterator it = entries_.begin();
@@ -181,40 +180,16 @@
   return net::ERR_FAILED;
 }
 
-class MemBackendImpl::MemIterator : public Backend::Iterator {
- public:
-  explicit MemIterator(base::WeakPtr<MemBackendImpl> backend)
-      : backend_(backend), current_(NULL) {
-  }
-
-  virtual int OpenNextEntry(Entry** next_entry,
-                            const CompletionCallback& callback) OVERRIDE {
-    if (!backend_)
-      return net::ERR_FAILED;
-
-    MemEntryImpl* node = backend_->rankings_.GetNext(current_);
-    // We should never return a child entry so iterate until we hit a parent
-    // entry.
-    while (node && node->type() != MemEntryImpl::kParentEntry)
-      node = backend_->rankings_.GetNext(node);
-    *next_entry = node;
-    current_ = node;
-
-    if (node) {
-      node->Open();
-      return net::OK;
-    }
-    return net::ERR_FAILED;
-  }
-
- private:
-  base::WeakPtr<MemBackendImpl> backend_;
-  MemEntryImpl* current_;
-};
-
-scoped_ptr<Backend::Iterator> MemBackendImpl::CreateIterator() {
-  return scoped_ptr<Backend::Iterator>(
-      new MemIterator(weak_factory_.GetWeakPtr()));
+int MemBackendImpl::OpenNextEntry(void** iter, Entry** next_entry,
+                                  const CompletionCallback& callback) {
+  if (OpenNextEntry(iter, next_entry))
+    return net::OK;
+
+  return net::ERR_FAILED;
+}
+
+void MemBackendImpl::EndEnumeration(void** iter) {
+  *iter = NULL;
 }
 
 void MemBackendImpl::OnExternalCacheHit(const std::string& key) {
@@ -312,6 +287,23 @@
   }
 }
 
+bool MemBackendImpl::OpenNextEntry(void** iter, Entry** next_entry) {
+  MemEntryImpl* current = reinterpret_cast<MemEntryImpl*>(*iter);
+  MemEntryImpl* node = rankings_.GetNext(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;
+
+  if (node)
+    node->Open();
+
+  return NULL != node;
+}
+
 void MemBackendImpl::TrimCache(bool empty) {
   MemEntryImpl* next = rankings_.GetPrev(NULL);
   if (!next)