Basic UkmService implementation

components/metrics_services_manager/metrics_services_manager.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 COMPONENTS_METRICS_SERVICES_MANAGER_METRICS_SERVICES_MANAGER_H_
 #define COMPONENTS_METRICS_SERVICES_MANAGER_METRICS_SERVICES_MANAGER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/metrics/field_trial.h"
 #include "base/threading/thread_checker.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace metrics {
 class MetricsService;
 class MetricsServiceClient;
 class MetricsStateManager;
 }
 
 namespace rappor {
 class RapporServiceImpl;
 }
 
+namespace ukm {
+class UkmService;
+}
+
 namespace variations {
 class VariationsService;
 }
 
 namespace metrics_services_manager {
 
 class MetricsServicesManagerClient;
 
 // MetricsServicesManager is a helper class for embedders that use the various
 // metrics-related services in a Chrome-like fashion: MetricsService (via its
@@ skipping 15 matching lines @@
   std::unique_ptr<const base::FieldTrial::EntropyProvider>
   CreateEntropyProvider();
 
   // Returns the MetricsService, creating it if it hasn't been created yet (and
   // additionally creating the MetricsServiceClient in that case).
   metrics::MetricsService* GetMetricsService();
 
   // Returns the RapporServiceImpl, creating it if it hasn't been created yet.
   rappor::RapporServiceImpl* GetRapporServiceImpl();
 
+  // Returns the RapporServiceImpl, creating it if it hasn't been created yet.

[rkaplow, 2017/01/02 23:23:03]

update comment

[Steven Holte, 2017/01/03 21:16:03]

Done.

+  ukm::UkmService* GetUkmService();
+
   // Returns the VariationsService, creating it if it hasn't been created yet.
   variations::VariationsService* GetVariationsService();
 
   // Should be called when a plugin loading error occurs.
   void OnPluginLoadingError(const base::FilePath& plugin_path);
 
   // Some embedders use this method to notify the metrics system when a
   // renderer process exits unexpectedly.
   void OnRendererProcessCrash();
 
@@ skipping 38 matching lines @@
 
   // The VariationsService, for server-side experiments infrastructure.
   std::unique_ptr<variations::VariationsService> variations_service_;
 
   DISALLOW_COPY_AND_ASSIGN(MetricsServicesManager);
 };
 
 }  // namespace metrics_services_manager
 
 #endif  // COMPONENTS_METRICS_SERVICES_MANAGER_METRICS_SERVICES_MANAGER_H_