Revert of Convert //net and //chromecast to std::unordered_*

net/disk_cache/memory/mem_backend_impl.h

 // 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.
 
 // See net/disk_cache/disk_cache.h for the public interface of the cache.
 
 #ifndef NET_DISK_CACHE_MEMORY_MEM_BACKEND_IMPL_H_
 #define NET_DISK_CACHE_MEMORY_MEM_BACKEND_IMPL_H_
 
 #include <stdint.h>
 
 #include <string>
-#include <unordered_map>
 
 #include "base/compiler_specific.h"
+#include "base/containers/hash_tables.h"
 #include "base/containers/linked_list.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string_split.h"
 #include "base/time/time.h"
 #include "net/disk_cache/disk_cache.h"
 #include "net/disk_cache/memory/mem_entry_impl.h"
 
 namespace net {
 class NetLog;
@@ skipping 64 matching lines @@
                        const CompletionCallback& callback) override;
   int CalculateSizeOfAllEntries(const CompletionCallback& callback) override;
   scoped_ptr<Iterator> CreateIterator() override;
   void GetStats(base::StringPairs* stats) override {}
   void OnExternalCacheHit(const std::string& key) override;
 
  private:
   class MemIterator;
   friend class MemIterator;
 
-  using EntryMap = std::unordered_map<std::string, MemEntryImpl*>;
+  typedef base::hash_map<std::string, MemEntryImpl*> EntryMap;
 
   // Deletes entries from the cache until the current size is below the limit.
   void EvictIfNeeded();
 
   EntryMap entries_;
 
   // Stored in increasing order of last use time, from least recently used to
   // most recently used.
   base::LinkedList<MemEntryImpl> lru_list_;
 
   int32_t max_size_;      // Maximum data size for this instance.
   int32_t current_size_;
 
   net::NetLog* net_log_;
 
   base::WeakPtrFactory<MemBackendImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MemBackendImpl);
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_MEMORY_MEM_BACKEND_IMPL_H_