[Chromecast] Moves persistent UMA client ID handling to common code.

chromecast/browser/metrics/platform_metrics_providers.h

-// Copyright 2014 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 CHROMECAST_BROWSER_METRICS_PLATFORM_METRICS_PROVIDERS_H_
-#define CHROMECAST_BROWSER_METRICS_PLATFORM_METRICS_PROVIDERS_H_
-
-#include "components/metrics/proto/system_profile.pb.h"
-
-namespace metrics {
-class MetricsService;
-}
-
-namespace chromecast {
-
-class CastService;
-
-namespace metrics {
-
-// Build-level hook for different platforms to provide data to MetricsService.
-void RegisterPlatformMetricsProviders(
-    ::metrics::MetricsService* metrics_service,
-    CastService* cast_servce);
-
-// Returns UMA client ID persisted in the platform.
-const std::string GetPlatformClientID(CastService* cast_servce);
-
-// Called when the UMA client ID has been set.
-void PlatformSetClientID(CastService* cast_servce,
-                         const std::string& client_id);
-
-}  // namespace metrics
-}  // namespace chromecast
-
-#endif  // CHROMECAST_BROWSER_METRICS_PLATFORM_METRICS_PROVIDERS_H_