Use kMetricsReportingEnabled instead of kStatsReporingPref on metrics side

chrome/browser/metrics/metrics_reporting_state.h

 // 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.
 
 #ifndef CHROME_BROWSER_METRICS_METRICS_REPORTING_STATE_H_
 #define CHROME_BROWSER_METRICS_METRICS_REPORTING_STATE_H_
 
 #include "base/callback.h"
 
 typedef base::Callback<void(bool)> OnMetricsReportingCallbackType;
 
 // Initiates a change to metrics reporting state to the new value of |enabled|.
 // Starts or stops the metrics service based on the new state and then runs
 // |callback_fn| (which can be null) with the updated state (as the operation
 // may fail). On platforms other than CrOS and Android, also updates the
 // underlying pref.
 // TODO(gayane): Support setting the pref on all platforms.
 void InitiateMetricsReportingChange(
     bool enabled,
     const OnMetricsReportingCallbackType& callback_fn);
 
-// Returns whether MetricsReporting can be modified by the user (except CrOS and
+// Returns whether MetricsReporting can be modified by the user (except
 // Android).
-bool IsMetricsReportingUserChangable();
+bool IsMetricsReportingPolicyManaged();
+
+// Initialize kMetricsReportingEnabled based on kStatsReportingPref device
+// setting and add an observer as it is the source of truth on Chrome OS.
+void SetupMetricsStateForChromeOS();
 
 #endif  // CHROME_BROWSER_METRICS_METRICS_REPORTING_STATE_H_