Revert "Update legacy Tuple-using code."

sandbox/linux/seccomp-bpf/codegen.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 "sandbox/linux/seccomp-bpf/codegen.h"
 
 #include <linux/filter.h>
 
 #include <limits>
 #include <utility>
@@ skipping 127 matching lines @@
 }
 
 size_t CodeGen::Offset(Node target) const {
   CHECK_LT(target, program_.size()) << "Bogus offset target node";
   return (program_.size() - 1) - target;
 }
 
 // TODO(mdempsky): Move into a general base::Tuple helper library.
 bool CodeGen::MemoKeyLess::operator()(const MemoKey& lhs,
                                       const MemoKey& rhs) const {
-  if (get<0>(lhs) != get<0>(rhs))
-    return get<0>(lhs) < get<0>(rhs);
-  if (get<1>(lhs) != get<1>(rhs))
-    return get<1>(lhs) < get<1>(rhs);
-  if (get<2>(lhs) != get<2>(rhs))
-    return get<2>(lhs) < get<2>(rhs);
-  if (get<3>(lhs) != get<3>(rhs))
-    return get<3>(lhs) < get<3>(rhs);
+  if (lhs.a != rhs.a)
+    return lhs.a < rhs.a;
+  if (lhs.b != rhs.b)
+    return lhs.b < rhs.b;
+  if (lhs.c != rhs.c)
+    return lhs.c < rhs.c;
+  if (lhs.d != rhs.d)
+    return lhs.d < rhs.d;
   return false;
 }
 
 }  // namespace sandbox