Add an override flag to enable metrics reporting.

components/metrics_services_manager/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 COMPONENTS_METRICS_SERVICES_MANAGER_METRICS_SERVICES_MANAGER_CLIENT_H_
 #define COMPONENTS_METRICS_SERVICES_MANAGER_METRICS_SERVICES_MANAGER_CLIENT_H_
 
 #include <memory>
 
 #include "base/callback_forward.h"
@@ skipping 39 matching lines @@
 
   // Returns whether metrics reporting is enabled.
   virtual bool IsMetricsReportingEnabled() = 0;
 
   // Whether the metrics services should record but not report metrics.
   virtual bool OnlyDoMetricsRecording() = 0;
 
   // Update the running state of metrics services managed by the embedder, for
   // example, crash reporting.
   virtual void UpdateRunningServices(bool may_record, bool may_upload) {}
+
+  // If the user has forced metrics collection on via the override flag.
+  virtual bool IsMetricsReportingEnabledForTesting();
 };
 
 }  // namespace metrics_services_manager
 
 #endif  // COMPONENTS_METRICS_SERVICES_MANAGER_METRICS_SERVICES_MANAGER_CLIENT_H_