Syntax and coverage checking added to Network Traffic Annotations.

chrome/browser/net/traffic_annotation/network_traffic_annotation_checker.h

Index: chrome/browser/net/traffic_annotation/network_traffic_annotation_checker.h
diff --git a/chrome/browser/net/traffic_annotation/network_traffic_annotation_checker.h b/chrome/browser/net/traffic_annotation/network_traffic_annotation_checker.h
new file mode 100644
index 0000000000000000000000000000000000000000..6a17816dad3d0d8f9307b92e278652cbf1f7c165
--- /dev/null
+++ b/chrome/browser/net/traffic_annotation/network_traffic_annotation_checker.h
@@ -0,0 +1,24 @@
+// Copyright (c) 2017 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.
+
+#ifndef CHROME_BROWSER_NET_TRAFFIC_ANNOTATION_NETWORK_TRAFFIC_ANNOTATION_CHECKER_H_
+#define CHROME_BROWSER_NET_TRAFFIC_ANNOTATION_NETWORK_TRAFFIC_ANNOTATION_CHECKER_H_
+
+#include <map>
+
+#include "net/traffic_annotation/network_traffic_annotation.h"
+
+class NetworkTrafficAnnotationChecker {
+ public:
+  NetworkTrafficAnnotationChecker();
+  ~NetworkTrafficAnnotationChecker();
+
+  void CheckAnnotation(
+      const net::NetworkTrafficAnnotationTag& traffic_annotation);
+
+ private:
+  std::map<const char*, const char*> visited_annotations_;
+};
+
+#endif  // CHROME_BROWSER_NET_TRAFFIC_ANNOTATION_NETWORK_TRAFFIC_ANNOTATION_CHECKER_H_