[counting_allocator] Chrome changes.

base/containers/hash_tables.h

 // Copyright (c) 2011 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.
 
 #ifndef BASE_CONTAINERS_HASH_TABLES_H_
 #define BASE_CONTAINERS_HASH_TABLES_H_
 
 #include <cstddef>
 #include <unordered_map>
 #include <unordered_set>
@@ skipping 22 matching lines @@
 struct hash<std::pair<Type1, Type2>> {
   std::size_t operator()(std::pair<Type1, Type2> value) const {
     return base::HashInts(value.first, value.second);
   }
 };
 
 }  // namespace BASE_HASH_NAMESPACE
 
 namespace base {
 
+#if defined(_LIBCPP_COUNTING_ALLOCATOR)
+#define HASH_CONTAINER_ALLOCATOR(group, type...) \
+    std::counting_allocator<type, std::allocation_group::group>
+#else
+#define HASH_CONTAINER_ALLOCATOR(group, type...) std::allocator<type>
+#endif
+
 // Use std::unordered_map instead.
 template <class Key,
           class T,
           class Hash = BASE_HASH_NAMESPACE::hash<Key>,
           class Pred = std::equal_to<Key>,
-          class Alloc = std::allocator<std::pair<const Key, T>>>
+          class Alloc = HASH_CONTAINER_ALLOCATOR(unordered_map, std::pair<const Key, T>)>
 using hash_map = std::unordered_map<Key, T, Hash, Pred, Alloc>;
 
 // Use std::unordered_multimap instead.
 template <class Key,
           class T,
           class Hash = BASE_HASH_NAMESPACE::hash<Key>,
           class Pred = std::equal_to<Key>,
-          class Alloc = std::allocator<std::pair<const Key, T>>>
+          class Alloc = HASH_CONTAINER_ALLOCATOR(unordered_multimap, std::pair<const Key, T>)>
 using hash_multimap = std::unordered_multimap<Key, T, Hash, Pred, Alloc>;
 
 // Use std::unordered_multiset instead.
 template <class Key,
           class Hash = BASE_HASH_NAMESPACE::hash<Key>,
           class Pred = std::equal_to<Key>,
-          class Alloc = std::allocator<Key>>
+          class Alloc = HASH_CONTAINER_ALLOCATOR(unordered_multiset, Key)>
 using hash_multiset = std::unordered_multiset<Key, Hash, Pred, Alloc>;
 
 // Use std::unordered_set instead.
 template <class Key,
           class Hash = BASE_HASH_NAMESPACE::hash<Key>,
           class Pred = std::equal_to<Key>,
-          class Alloc = std::allocator<Key>>
+          class Alloc = HASH_CONTAINER_ALLOCATOR(unordered_set, Key)>
 using hash_set = std::unordered_set<Key, Hash, Pred, Alloc>;
 
+#undef HASH_CONTAINER_ALLOCATOR
+
 }  // namespace base
 
 #endif  // BASE_CONTAINERS_HASH_TABLES_H_