Extracting NetLog inner classes into their own classes.

net/log/net_log_source.h

+// 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_SOURCE_H_
+#define NET_LOG_NET_LOG_SOURCE_H_
+
+#include <stdint.h>
+
+#include "net/base/net_export.h"
+#include "net/log/net_log_parameters_callback.h"
+#include "net/log/net_log_source_type.h"
+
+namespace base {
+class DictionaryValue;
+class Value;
+}
+
+namespace net {
+
+// Identifies the entity that generated this log. The |id| field should
+// uniquely identify the source, and is used by log observers to infer
+// message groupings. Can use NetLog::NextID() to create unique IDs.
+struct NET_EXPORT NetLogSource {
+  static const uint32_t kInvalidId;
+
+  NetLogSource();
+  NetLogSource(NetLogSourceType type, uint32_t id);
+  bool IsValid() const;
+
+  // Adds the source to a DictionaryValue containing event parameters,
+  // using the name "source_dependency".
+  void AddToEventParameters(base::DictionaryValue* event_params) const;
+
+  // Returns a callback that returns a dictionary with a single entry
+  // named "source_dependency" that describes |this|.
+  NetLogParametersCallback ToEventParametersCallback() const;
+
+  // Attempts to extract a NetLogSource from a set of event parameters.  Returns
+  // true and writes the result to |source| on success.  Returns false and
+  // makes |source| an invalid source on failure.
+  // TODO(mmenke):  Long term, we want to remove this.
+  static bool FromEventParameters(base::Value* event_params,
+                                  NetLogSource* source);
+
+  NetLogSourceType type;
+  uint32_t id;
+};
+
+}  // namespace net
+
+#endif  // NET_LOG_NET_LOG_SOURCE_H_