Adding reporting of metrics sampling rate.

chrome/browser/metrics/chrome_metrics_service_client.cc

Index: chrome/browser/metrics/chrome_metrics_service_client.cc
diff --git a/chrome/browser/metrics/chrome_metrics_service_client.cc b/chrome/browser/metrics/chrome_metrics_service_client.cc
index 8bb2f6c2e948bd44dead435b390dc26614fb2ba7..334dd4ba98464826ea2a990480d270b8fca8f8f5 100644
--- a/chrome/browser/metrics/chrome_metrics_service_client.cc
+++ b/chrome/browser/metrics/chrome_metrics_service_client.cc
@@ -29,6 +29,7 @@
 #include "chrome/browser/metrics/chrome_stability_metrics_provider.h"
 #include "chrome/browser/metrics/https_engagement_metrics_provider.h"
 #include "chrome/browser/metrics/metrics_reporting_state.h"
+#include "chrome/browser/metrics/sampling_metrics_provider.h"
 #include "chrome/browser/metrics/subprocess_metrics_provider.h"
 #include "chrome/browser/metrics/time_ticks_experiment_win.h"
 #include "chrome/browser/sync/chrome_sync_client.h"
@@ -456,6 +457,10 @@ void ChromeMetricsServiceClient::Initialize() {
       std::unique_ptr<metrics::MetricsProvider>(
           new metrics::CallStackProfileMetricsProvider));
 
+  metrics_service_->RegisterMetricsProvider(
+      std::unique_ptr<metrics::MetricsProvider>(
+          new metrics::SamplingMetricsProvider));
+
 #if BUILDFLAG(ANDROID_JAVA_UI)
   metrics_service_->RegisterMetricsProvider(
       std::unique_ptr<metrics::MetricsProvider>(