Add a datatype for supervised user whitelists.

sync/protocol/managed_user_whitelist_specifics.proto

Index: sync/protocol/managed_user_whitelist_specifics.proto
diff --git a/sync/protocol/managed_user_whitelist_specifics.proto b/sync/protocol/managed_user_whitelist_specifics.proto
new file mode 100644
index 0000000000000000000000000000000000000000..a0acf549d76432f34727c556b3a455df947f6461
--- /dev/null
+++ b/sync/protocol/managed_user_whitelist_specifics.proto
@@ -0,0 +1,25 @@
+// Copyright (c) 2014 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 supervised user whitelists.
+
+// 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;
+
+// Properties of supervised user whitelist sync objects.
+// The fields here are a subset of the fields in an ExtensionSpecifics.
+message ManagedUserWhitelistSpecifics {
+  // Globally unique id for this whitelist.
+  optional string id = 1;

[Nicolas Zea, 2014/12/15 22:45:36]

perhaps mention that this is a webstore id?

[Bernhard Bauer, 2014/12/15 22:56:14]

Done.

+
+  // The name of the whitelist.

[Nicolas Zea, 2014/12/15 22:45:36]

One word of caution, not sure if it necessarily applies here. Extensions has the
problem that it syncs the extension name and version, which are automatically
updated based on what the extension author does. As such, if a user deletes an
extension on one machine, but another machine upgrades to a new version of the
extension, the conflict resolution logic will undelete the extension (since the
update will have a new version, and entity modification > entity deletion).

If that's not an issue here (because for example they entities are read only on
the client, or the name can never change), then feel free to ignore.

[Bernhard Bauer, 2014/12/15 22:56:14]

Yeah, we neatly sidestep all of these problems by never allowing any local
changes :)

+  optional string name = 2;
+}