Enable sync for the settings from the Extension Settings API.

chrome/browser/extensions/extension_settings_sync_helper.cc

+// Copyright (c) 2011 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.
+
+#include "chrome/browser/extensions/extension_settings_sync_helper.h"
+
+#include "base/json/json_writer.h"
+#include "chrome/browser/sync/protocol/extension_setting_specifics.pb.h"
+
+/* static */
+SyncData ExtensionSettingsSyncHelper::CreateData(
+    const std::string& extension_id,
+    const std::string& key,
+    const Value& value) {
+  sync_pb::EntitySpecifics specifics;
+  sync_pb::ExtensionSettingSpecifics* setting_specifics =
+      specifics.MutableExtension(sync_pb::extension_setting);
+  setting_specifics->set_extension_id(extension_id);
+  setting_specifics->set_key(key);
+  std::string value_as_json;
+  base::JSONWriter::Write(&value, false, &value_as_json);
+  setting_specifics->set_value(value_as_json);
+  return SyncData::CreateLocalData(extension_id + "/" + key, key, specifics);
+}
+
+/* static */
+SyncChange ExtensionSettingsSyncHelper::CreateAdd(
+    const std::string& extension_id,
+    const std::string& key,
+    const Value& value) {
+  return SyncChange(
+      SyncChange::ACTION_ADD, CreateData(extension_id, key, value));
+}
+
+/* static */
+SyncChange ExtensionSettingsSyncHelper::CreateUpdate(
+    const std::string& extension_id,
+    const std::string& key,
+    const Value& value) {
+  return SyncChange(
+      SyncChange::ACTION_UPDATE, CreateData(extension_id, key, value));
+}
+
+/* static */
+SyncChange ExtensionSettingsSyncHelper::CreateDelete(
+    const std::string& extension_id, const std::string& key) {
+  DictionaryValue no_value;
+  return SyncChange(
+      SyncChange::ACTION_DELETE, CreateData(extension_id, key, no_value));
+}