Extracted NetLog class's inner enum types into their own enum classes and

net/log/net_log_event_type.h

Index: net/log/net_log_event_type.h
diff --git a/net/log/net_log_event_type.h b/net/log/net_log_event_type.h
new file mode 100644
index 0000000000000000000000000000000000000000..d9d4bf60abab7f5d3a3b4fa5b3b2c415d5774c91
--- /dev/null
+++ b/net/log/net_log_event_type.h
@@ -0,0 +1,27 @@
+// 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.
+
+#ifndef NET_LOG_NET_LOG_EVENT_TYPE_H_
+#define NET_LOG_NET_LOG_EVENT_TYPE_H_
+
+namespace net {
+
+enum class NetLogEventType {
+#define EVENT_TYPE(label) label,
+#include "net/log/net_log_event_type_list.h"
+#undef EVENT_TYPE
+  COUNT
+};
+
+// The 'phase' of an event trace (whether it marks the beginning or end
+// of an event.).
+enum class NetLogEventPhase {
+  NONE,
+  BEGIN,
+  END,
+};
+
+}  // namespace net
+
+#endif  // NET_LOG_NET_LOG_EVENT_TYPE_H_