FYI: Control Data + Per-Device Metadata

sync/protocol/per_device_specifics.proto

+// 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.
+//
+// Sync protocol datatype extension for nigori keys.
+
+// Update proto_value_conversions{.h,.cc,_unittest.cc} if you change
+// any fields in this file.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+option retain_unknown_fields = true;
+
+package sync_pb;
+
+// Information about a device that is running a sync-enabled Chrome browser.
+// We are mapping the unique per-device cache guid to more specific information
+// about the device.
+message DeviceInformation {
+  optional string cache_guid = 1;
+
+  // The name of the device is dependent on the OS running the Chrome instance.
+  // On a Chromebook this is "Chromebook", on Linux the distribution name, on
+  // Mac OSX the hadware model name and on Windows the computer name.
+  optional string name = 2;
+
+  // The platform of the device (ChromeOS, Linux, Mac, or Windows).
+  optional string platform = 3;
+
+  // The Chrome version of the sync-enabled Chrome browser.
+  optional string chrome_version = 4;
+}
+
+message PerDeviceSpecifics {

[rlarocque, 2012/08/11 01:31:52]

Feel free to hold a bike-shed discussion about the contents of this file.

(Seriously.  This will be your last chance to recommend different names or
alternate protobuf structures.)

+  optional DeviceInformation device_information = 1;
+}