Query the existence other forms of browsing history.

sync/protocol/history_status.proto

+// Copyright 2016 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
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+option retain_unknown_fields = true;
+
+package sync_pb;
+
+message HistoryStatusRequest {
+}
+
+// Response to a history status request.
+message HistoryStatusResponse {
+  // Minimal time to wait before issuing another request.
+  optional int32 min_poll_interval_seconds = 1 [default = 3600];
+
+  // Indicates whether the history corpuses have any derived data for a user.
+  optional bool has_derived_data = 2;
+}