Tool added to extract network traffic annotations.

tools/traffic_annotation/auditor/BUILD.gn

+# Copyright 2016 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.
+
+import("//third_party/protobuf/proto_library.gni")
+
+# Works only on desktop platforms.
+assert(is_win || is_linux || is_mac)
+
+proto_library("chrome_settings_full_runtime") {
+  proto_out_dir = "/tools/traffic_annotation"
+
+  cc_include = "components/policy/proto/policy_proto_export.h"
+
+  sources = [
+    "$root_gen_dir" +
+        "/components/policy/proto/cloud_policy_full_runtime.proto",
+    "$root_gen_dir" +
+        "/components/policy/proto/chrome_settings_full_runtime.proto",
+  ]
+
+  use_protobuf_full = true
+
+  deps = [
+    "//components/policy:full_runtime_code_generate",
+    "//third_party/protobuf:protobuf_full",
+  ]
+}
+
+proto_library("traffic_annotation") {
+  sources = [
+    "../traffic_annotation.proto",
+  ]
+
+  import_dirs = [ "$root_gen_dir" + "/components/policy/proto" ]
+
+  deps = [
+    ":chrome_settings_full_runtime",
+  ]
+
+  use_protobuf_full = true
+}
+
+group("traffic_annotation_auditor") {
+  deps = [
+    ":traffic_annotation",
+    "//third_party/protobuf:protobuf_full",
+  ]
+}