[Sync] Add a simple UI to sync-internals to create UserEvents.

components/sync/driver/about_sync_util.h

 // Copyright 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 COMPONENTS_SYNC_DRIVER_ABOUT_SYNC_UTIL_H_
 #define COMPONENTS_SYNC_DRIVER_ABOUT_SYNC_UTIL_H_
 
 #include <memory>
 
 #include "components/version_info/version_info.h"
@@ skipping 18 matching lines @@
 extern const char kAboutJS[];
 extern const char kChromeSyncJS[];
 extern const char kDataJS[];
 extern const char kEventsJS[];
 extern const char kSearchJS[];
 extern const char kSyncIndexJS[];
 extern const char kSyncLogJS[];
 extern const char kSyncNodeBrowserJS[];
 extern const char kSyncSearchJS[];
 extern const char kTypesJS[];
+extern const char kUserEventsJS[];
 
 // Message handlers.
 // Must match the constants used in the resource files.
 extern const char kDispatchEvent[];
 extern const char kGetAllNodes[];
 extern const char kGetAllNodesCallback[];
 extern const char kRegisterForEvents[];
 extern const char kRegisterForPerTypeCounters[];
 extern const char kRequestListOfTypes[];
 extern const char kRequestUpdatedAboutInfo[];
+extern const char kRequestUserEventsVisibility[];
+extern const char kUserEventsVisibilityCallback[];
+extern const char kWriteUserEvent[];
 
 // Other strings.
 // Must match the constants used in the resource files.
 extern const char kCommit[];
 extern const char kCounters[];
 extern const char kCounterType[];
 extern const char kModelType[];
 extern const char kOnAboutInfoUpdated[];
 extern const char kOnCountersUpdated[];
 extern const char kOnProtocolEvent[];
 extern const char kOnReceivedListOfTypes[];
 extern const char kStatus[];
 extern const char kTypes[];
 extern const char kUpdate[];
 
 // This function returns a DictionaryValue which contains all the information
 // required to populate the 'About' tab of about:sync.
 // Note that |service| may be null.
 std::unique_ptr<base::DictionaryValue> ConstructAboutInformation(
     SyncService* service,
     version_info::Channel channel);
 
 }  // namespace sync_ui_util
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_DRIVER_ABOUT_SYNC_UTIL_H_