Update the tcmalloc vendor branch to r144 (gperftools 2.0).

third_party/tcmalloc/vendor/src/libc_override_osx.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 57 matching lines @@
 // punt and don't implement our own posix_memalign.  Apps that really
 // care can use tc_posix_memalign directly.
 
 #ifndef TCMALLOC_LIBC_OVERRIDE_OSX_INL_H_
 #define TCMALLOC_LIBC_OVERRIDE_OSX_INL_H_
 
 #include <config.h>
 #ifdef HAVE_FEATURES_H
 #include <features.h>
 #endif
-#include <google/tcmalloc.h>
+#include <gperftools/tcmalloc.h>
 
 #if !defined(__APPLE__)
 # error libc_override_glibc-osx.h is for OS X distributions only.
 #endif
 
 #include <AvailabilityMacros.h>
 #include <malloc/malloc.h>
 
+// from AvailabilityMacros.h
+#if defined(MAC_OS_X_VERSION_10_6) && \
+    MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_6
+extern "C" {
+  // This function is only available on 10.6 (and later) but the
+  // LibSystem headers do not use AvailabilityMacros.h to handle weak
+  // importing automatically.  This prototype is a copy of the one in
+  // <malloc/malloc.h> with the WEAK_IMPORT_ATTRBIUTE added.
+  extern malloc_zone_t *malloc_default_purgeable_zone(void)
+      WEAK_IMPORT_ATTRIBUTE;
+}
+#endif
+
 // We need to provide wrappers around all the libc functions.
 namespace {
 size_t mz_size(malloc_zone_t* zone, const void* ptr) {
   if (MallocExtension::instance()->GetOwnership(ptr) != MallocExtension::kOwned)
     return 0;  // malloc_zone semantics: return 0 if we don't own the memory
 
   // TODO(csilvers): change this method to take a const void*, one day.
   return MallocExtension::instance()->GetAllocatedSize(const_cast<void*>(ptr));
 }
 
@@ skipping 131 matching lines @@
   tcmalloc_zone.version = 6;
   tcmalloc_zone.free_definite_size = NULL;
   tcmalloc_zone.memalign = &mz_memalign;
   tcmalloc_introspection.zone_locked = &mi_zone_locked;
 
   // Request the default purgable zone to force its creation. The
   // current default zone is registered with the purgable zone for
   // doing tiny and small allocs.  Sadly, it assumes that the default
   // zone is the szone implementation from OS X and will crash if it
   // isn't.  By creating the zone now, this will be true and changing
-  // the default zone won't cause a problem.  (OS X 10.6 and higher.)
-  malloc_default_purgeable_zone();
+  // the default zone won't cause a problem.  This only needs to
+  // happen when actually running on OS X 10.6 and higher (note the
+  // ifdef above only checks if we were *compiled* with 10.6 or
+  // higher; at runtime we have to check if this symbol is defined.)
+  if (malloc_default_purgeable_zone) {
+    malloc_default_purgeable_zone();
+  }
 #endif
 
   // Register the tcmalloc zone. At this point, it will not be the
   // default zone.
   malloc_zone_register(&tcmalloc_zone);
 
   // Unregister and reregister the default zone.  Unregistering swaps
   // the specified zone with the last one registered which for the
   // default zone makes the more recently registered zone the default
   // zone.  The default zone is then re-registered to ensure that
   // allocations made from it earlier will be handled correctly.
   // Things are not guaranteed to work that way, but it's how they work now.
   malloc_zone_t *default_zone = malloc_default_zone();
   malloc_zone_unregister(default_zone);
   malloc_zone_register(default_zone);
 }
 
 #endif  // TCMALLOC_LIBC_OVERRIDE_OSX_INL_H_