Split the policy refresh rate preference into user- and device-policy refresh rate.

chrome/browser/policy/proto/chrome_device_policy.proto

 // 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.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package enterprise_management;
 
 message DevicePolicyRefreshRateProto {
   // In milliseconds.
-  optional int64 policy_refresh_rate = 1;
+  optional int64 device_policy_refresh_rate = 1;
 }
 
 message UserWhitelistProto {
   repeated string user_whitelist = 1;
 }
 
 message AllowNewUsersProto {
   // Determines whether we allow arbitrary users to log into the device.
   // Should default to true.
   // This interacts with the UserWhitelistProto as follows:
@@ skipping 41 matching lines @@
   optional string proxy_server = 2;
   optional string proxy_pac_url = 3;
   optional string proxy_bypass_list = 4;
 }
 
 message CameraEnabledProto {
   optional bool camera_enabled = 1;
 }
 
 message ChromeDeviceSettingsProto {
-  optional DevicePolicyRefreshRateProto policy_refresh_rate = 1;
+  optional DevicePolicyRefreshRateProto device_policy_refresh_rate = 1;
   optional UserWhitelistProto user_whitelist = 2;
   optional GuestModeEnabledProto guest_mode_enabled = 3;
   optional DeviceProxySettingsProto device_proxy_settings = 4;
   optional CameraEnabledProto camera_enabled = 5;
   optional ShowUserNamesOnSigninProto show_user_names = 6;
   optional DataRoamingEnabledProto data_roaming_enabled = 7;
   optional AllowNewUsersProto allow_new_users = 8;
 }