sync: Add DeviceInfo protobuf and supporting code

chrome/browser/sync/glue/device_info.h

+// Copyright (c) 2012 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_SYNC_GLUE_DEVICE_INFO_H_
+#define CHROME_BROWSER_SYNC_GLUE_DEVICE_INFO_H_
+
+#include <string>

[Nicolas Zea, 2012/09/26 01:50:59]

newline after

[rlarocque, 2012/09/26 20:44:36]

Done.

+#include "base/bind.h"
+#include "sync/protocol/sync.pb.h"
+
+namespace browser_sync {
+
+// A class that holds information regarding the properties of a device.
+//
+// These objects do not contain enough information to uniquely identify devices.
+// Two different devices may end up generating identical DeviceInfos.
+class DeviceInfo {
+ public:
+  DeviceInfo();
+  DeviceInfo(const std::string& client_name,
+             const std::string& sync_user_agent,
+             const sync_pb::SyncEnums::DeviceType device_type);
+  ~DeviceInfo();
+
+  const std::string& client_name() const;
+  const std::string& sync_user_agent() const;

[Nicolas Zea, 2012/09/26 01:50:59]

Does anything care about this? It seems odd to expose a sync internal value like
this, and expect other services to parse it for whatever info they need.

[rlarocque, 2012/09/26 20:44:36]

I added this at Raz's suggestion.  It's meant to make this easier to process on
the server.

+  sync_pb::SyncEnums::DeviceType device_type() const;
+
+  // Compares this object's fields with another's.
+  bool Equals(const DeviceInfo& other) const;
+
+  static sync_pb::SyncEnums::DeviceType GetLocalDeviceType();
+  static void CreateLocalDeviceInfo(
+      base::Callback<void(const DeviceInfo& local_info)> callback);
+
+  // Helper to construct a user agent string (ASCII) suitable for use by
+  // the syncapi for any HTTP communication. This string is used by the sync
+  // backend for classifying client types when calculating statistics.
+  static std::string MakeUserAgentForSyncApi();
+
+ private:
+  static void CreateLocalDeviceInfoContinuation(
+      base::Callback<void(const DeviceInfo& local_info)> callback,
+      const std::string& session_name);
+
+  std::string client_name_;

[Nicolas Zea, 2012/09/26 01:50:59]

can these be const?

[rlarocque, 2012/09/26 20:44:36]

Sure, let's do that.

+  std::string sync_user_agent_;
+  sync_pb::SyncEnums::DeviceType device_type_;
+};
+
+}
+
+#endif  // CHROME_BROWSER_SYNC_GLUE_DEVICE_INFO_H_