[NOT TO COMMIT!] Merge Chromium-specific changes in tcmalloc thru. the original gperftools r136.

third_party/tcmalloc/chromium/src/base/vdso_support.cc

 // Copyright (c) 2008, 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 22 matching lines @@
 // Allow dynamic symbol lookup in the kernel VDSO page.
 //
 // VDSOSupport -- a class representing kernel VDSO (if present).
 //
 
 #include "base/vdso_support.h"
 
 #ifdef HAVE_VDSO_SUPPORT     // defined in vdso_support.h
 
 #include <fcntl.h>
-#include <stddef.h>   // for ptrdiff_t
+#include <stddef.h>   // for std::ptrdiff_t
 
 #include "base/atomicops.h"  // for MemoryBarrier
+#include "base/logging.h"
 #include "base/linux_syscall_support.h"
-#include "base/logging.h"
 #include "base/dynamic_annotations.h"
 #include "base/basictypes.h"  // for COMPILE_ASSERT
 
 using base::subtle::MemoryBarrier;
 
 #ifndef AT_SYSINFO_EHDR
 #define AT_SYSINFO_EHDR 33
 #endif
 
 namespace base {
@@ skipping 122 matching lines @@
 // ensure it here, with a global constructor of our own.  This
 // is an allowed exception to the normal rule against non-trivial
 // global constructors.
 static class VDSOInitHelper {
  public:
   VDSOInitHelper() { VDSOSupport::Init(); }
 } vdso_init_helper;
 }
 
 #endif  // HAVE_VDSO_SUPPORT