Enable TCMalloc doubly-linked freelist in release builds

third_party/tcmalloc/chromium/src/free_list.h

 // Copyright (c) 2011, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 25 matching lines @@
 // how much space a node in the freelist needs so that SizeMap can
 // create large enough size classes.
 
 #ifndef TCMALLOC_FREE_LIST_H_
 #define TCMALLOC_FREE_LIST_H_
 
 #include <stddef.h>
 #include "internal_logging.h"  // For CRASH() macro.
 #include "linked_list.h"
 
+// Remove to enable singly linked lists (the default for open source tcmalloc).
+#define TCMALLOC_USE_DOUBLYLINKED_FREELIST
+
 namespace tcmalloc {
 
-#ifdef TCMALLOC_USE_DOUBLYLINKED_FREELIST
+#if defined(TCMALLOC_USE_DOUBLYLINKED_FREELIST)
 
 // size class information for common.h.
 static const bool kSupportsDoublyLinkedList = true;
 
 void *FL_Next(void *t);
 void FL_Init(void *t);
 void FL_Push(void **list, void *element);
 void *FL_Pop(void **list);
 void FL_PopRange(void **head, int n, void **start, void **end);
 void FL_PushRange(void **head, void *start, void *end);
@@ skipping 36 matching lines @@
 
 inline size_t FL_Size(void *head) {
   return SLL_Size(head);
 }
 
 #endif // TCMALLOC_USE_DOUBLYLINKED_FREELIST
 
 } // namespace tcmalloc
 
 #endif // TCMALLOC_FREE_LIST_H_