Standardize "net" category trace events

net/log/trace_constants.h

Index: net/log/trace_constants.h
diff --git a/net/log/trace_constants.h b/net/log/trace_constants.h
new file mode 100644
index 0000000000000000000000000000000000000000..bb509a6c1110bbf1d1a05dca6d40dbab246d834a
--- /dev/null
+++ b/net/log/trace_constants.h
@@ -0,0 +1,17 @@
+// 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_TRACE_CONSTANTS_H_

[mmenke, 2016/12/01 16:16:14]

We aren't consistent about it, but this should probably be in net/base (To avoid
circular dependencies, at the directory level.  We do have a lot of them
already, but no reason to add another unless we get something from it)

[xunjieli, 2016/12/01 23:38:11]

Done.

+#define NET_LOG_TRACE_CONSTANTS_H_
+
+#include "net/base/net_export.h"
+
+namespace net {
+
+// Net Category used in Tracing.
+NET_EXPORT_PRIVATE extern const char kNetTracingCategory[];
+
+}  // namespace net
+
+#endif  // NET_LOG_TRACE_CONSTANTS_H_