Don't override system malloc when built with LeakSanitizer.

base/process_util_linux.cc

 // Copyright (c) 2012 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/process_util.h"
 
 #include <dirent.h>
 #include <malloc.h>
 #include <sys/time.h>
 #include <sys/types.h>
@@ skipping 51 matching lines @@
   LOG(FATAL) << "Out of memory.";
 }
 
 void OnNoMemory() {
   OnNoMemorySize(0);
 }
 
 }  // namespace
 
 #if !defined(ADDRESS_SANITIZER) && !defined(MEMORY_SANITIZER) && \
-    !defined(THREAD_SANITIZER)
+    !defined(THREAD_SANITIZER) && !defined(LEAK_SANITIZER)
 
 #if defined(LIBC_GLIBC) && !defined(USE_TCMALLOC)
 
 extern "C" {
 void* __libc_malloc(size_t size);
 void* __libc_realloc(void* ptr, size_t size);
 void* __libc_calloc(size_t nmemb, size_t size);
 void* __libc_valloc(size_t size);
 void* __libc_pvalloc(size_t size);
 void* __libc_memalign(size_t alignment, size_t size);
@@ skipping 127 matching lines @@
     int score_len = static_cast<int>(score_str.length());
     return (score_len == file_util::WriteFile(oom_file,
                                               score_str.c_str(),
                                               score_len));
   }
 
   return false;
 }
 
 }  // namespace base