mac: Hook up allocator shim.

base/process/memory.cc

 // Copyright 2014 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.
 
 #include "base/debug/alias.h"
 #include "base/logging.h"
 #include "base/process/memory.h"
 #include "build/build_config.h"
 
 namespace base {
@@ skipping 12 matching lines @@
 }
 
 }  // namespace
 
 void TerminateBecauseOutOfMemory(size_t size) {
   OnNoMemory(size);
 }
 
 #endif
 
-// Defined in memory_mac.mm for Mac.
-#if !defined(OS_MACOSX)
-
 bool UncheckedCalloc(size_t num_items, size_t size, void** result) {
   const size_t alloc_size = num_items * size;
 
   // Overflow check
   if (size && ((alloc_size / size) != num_items)) {
     *result = NULL;
     return false;
   }
 
   if (!UncheckedMalloc(alloc_size, result))
     return false;
 
   memset(*result, 0, alloc_size);
   return true;
 }
 
-#endif
-
 }  // namespace base