Allow std::unordered_*.

components/metrics/leak_detector/call_stack_table.h

 // Copyright 2015 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 COMPONENTS_METRICS_LEAK_DETECTOR_CALL_STACK_TABLE_H_
 #define COMPONENTS_METRICS_LEAK_DETECTOR_CALL_STACK_TABLE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 46 matching lines @@
     uint32_t net_num_allocs;
   };
 
   // Total number of allocs and frees in this table.
   uint32_t num_allocs_;
   uint32_t num_frees_;
 
   // Hash table containing entries. Uses CustomAllocator to avoid recursive
   // malloc hook invocation when analyzing allocs and frees.
   using TableEntryAllocator =
-      STLAllocator<std::pair<const CallStack*, Entry>, CustomAllocator>;
+      STLAllocator<std::pair<const CallStack* const, Entry>, CustomAllocator>;
   base::hash_map<const CallStack*,
                  Entry,
                  StoredHash,
                  std::equal_to<const CallStack*>,
                  TableEntryAllocator> entry_map_;
 
   // For detecting leak patterns in incoming allocations.
   LeakAnalyzer leak_analyzer_;
 
   DISALLOW_COPY_AND_ASSIGN(CallStackTable);
 };
 
 }  // namespace leak_detector
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_LEAK_DETECTOR_CALL_STACK_TABLE_H_