[Chromecast] Add net logging.

chromecast/browser/cast_net_log.h

+// Copyright 2015 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 CHROMECAST_BROWSER_CAST_NET_LOG_H_
+#define CHROMECAST_BROWSER_CAST_NET_LOG_H_
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "net/log/write_to_file_net_log_observer.h"
+
+namespace chromecast {
+
+class CastNetLog : public net::NetLog {
+ public:
+  CastNetLog();
+  ~CastNetLog() override;
+
+ private:
+  scoped_ptr<net::WriteToFileNetLogObserver> write_to_file_observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(CastNetLog);
+};
+
+}  // namespace chromecast
+
+#endif  // CHROMECAST_BROWSER_CAST_NET_LOG_H_