Splitting the concept of UMA consent, and should UMA report.

chrome/browser/metrics/chrome_metrics_services_manager_client.h

 // Copyright 2015 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_CHROME_METRICS_SERVICES_MANAGER_CLIENT_H_
 #define CHROME_BROWSER_METRICS_CHROME_METRICS_SERVICES_MANAGER_CLIENT_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/threading/thread_checker.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 #include "components/metrics_services_manager/metrics_services_manager_client.h"
 
 class PrefService;
 
 namespace metrics {
+class EnabledStateProvider;
 class MetricsStateManager;
 }
 
 // Provides a //chrome-specific implementation of MetricsServicesManagerClient.
 class ChromeMetricsServicesManagerClient
     : public metrics_services_manager::MetricsServicesManagerClient {
  public:
   explicit ChromeMetricsServicesManagerClient(PrefService* local_state);
   ~ChromeMetricsServicesManagerClient() override;
 
  private:
+  class ChromeEnabledStateProvider;

[Alexei Svitkine (slow), 2016/05/11 17:16:28]

Nit: Suggest making this a class in the anon namespace rather than a member
class. Since you use the interface for the member, no need to declare it in the
header.

[jwd, 2016/05/11 18:31:38]

I made it a member class to get access to
ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled() through
ChromeMetricsServicesManagerClient's friendship. This seemed nicer than exposing
a public method on ChromeMetricsServicesManagerClient, and give
ChromeEnabledStateProvider a pointer to the ChromeMetricsServicesManagerClient
instance.

+
   // metrics_services_manager::MetricsServicesManagerClient:
   std::unique_ptr<rappor::RapporService> CreateRapporService() override;
   std::unique_ptr<variations::VariationsService> CreateVariationsService()
       override;
   std::unique_ptr<metrics::MetricsServiceClient> CreateMetricsServiceClient()
       override;
   net::URLRequestContextGetter* GetURLRequestContext() override;
   bool IsSafeBrowsingEnabled(const base::Closure& on_update_callback) override;
   bool IsMetricsReportingEnabled() override;
   bool OnlyDoMetricsRecording() override;
 
   // Gets the MetricsStateManager, creating it if it has not already been
   // created.
   metrics::MetricsStateManager* GetMetricsStateManager();
 
   // MetricsStateManager which is passed as a parameter to service constructors.
   std::unique_ptr<metrics::MetricsStateManager> metrics_state_manager_;
 
+  // EnabledStateProvider to communicate if the client has consented to metrics
+  // reporting, and if it's enabled.
+  std::unique_ptr<metrics::EnabledStateProvider> enabled_state_provider_;
+
   // Ensures that all functions are called from the same thread.
   base::ThreadChecker thread_checker_;
 
   // Weak pointer to the local state prefs store.
   PrefService* local_state_;
 
   // Subscription to SafeBrowsing service state changes.
   std::unique_ptr<safe_browsing::SafeBrowsingService::StateSubscription>
       sb_state_subscription_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeMetricsServicesManagerClient);
 };
 
 #endif  // CHROME_BROWSER_METRICS_CHROME_METRICS_SERVICES_MANAGER_CLIENT_H_