Introduce linux_filter.h and replace #include <linux/filter.h>

sandbox/linux/bpf_dsl/codegen_unittest.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/bpf_dsl/codegen.h"
 
-#include <linux/filter.h>
-
 #include <map>
 #include <utility>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/md5.h"
 #include "base/strings/string_piece.h"
+#include "sandbox/linux/system_headers/linux_filter.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace sandbox {
 namespace {
 
 // Hash provides an abstraction for building "hash trees" from BPF
 // control flow graphs, and efficiently identifying equivalent graphs.
 //
 // For simplicity, we use MD5, because base happens to provide a
 // convenient API for its use. However, any collision-resistant hash
@@ skipping 368 matching lines @@
   // Branching again to the same target nodes should require only one
   // new instruction, as we can reuse the previous branch's jumps.
   CodeGen::Node two =
       MakeInstruction(BPF_JMP + BPF_JEQ + BPF_K, 1, nodes[0], nodes[1]);
   EXPECT_EQ(one + 1, two);  // XXX: Implementation detail!
   RunTest(two);
 }
 
 }  // namespace
 }  // namespace sandbox