Register EntropySourceProvider for iOS

Register EntropySourceProvider in ios_chrome_metrics_service_client so
that all iOS reports will have low entropy source values populated.

Bug: b/172461970
Change-Id: Ib216094ed532824fde69f97c7c772bf7bbabd25e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2528308Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Alexei Svitkine <asvitkine@chromium.org>
Auto-Submit: Weilun Shi <sweilun@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825865}

ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm

@@ -34,6 +34,7 @@
 #include "components/metrics/cpu_metrics_provider.h"
 #include "components/metrics/demographics/demographic_metrics_provider.h"
 #include "components/metrics/drive_metrics_provider.h"
+#include "components/metrics/entropy_state_provider.h"
 #include "components/metrics/field_trials_provider.h"
 #include "components/metrics/metrics_log_uploader.h"
 #include "components/metrics/metrics_pref_names.h"
@@ -264,6 +265,8 @@ void IOSChromeMetricsServiceClient::Initialize() {
 }
 
 void IOSChromeMetricsServiceClient::RegisterMetricsServiceProviders() {
+  PrefService* local_state = GetApplicationContext()->GetLocalState();
+
   metrics_service_->RegisterMetricsProvider(
       std::make_unique<metrics::NetworkMetricsProvider>(
           base::BindRepeating(&GetNetworkConnectionTrackerAsync)));
@@ -272,8 +275,7 @@ void IOSChromeMetricsServiceClient::RegisterMetricsServiceProviders() {
       std::make_unique<OmniboxMetricsProvider>());
 
   auto stability_metrics_provider =
-      std::make_unique<IOSChromeStabilityMetricsProvider>(
-          GetApplicationContext()->GetLocalState());
+      std::make_unique<IOSChromeStabilityMetricsProvider>(local_state);
   stability_metrics_provider_ = stability_metrics_provider.get();
   metrics_service_->RegisterMetricsProvider(
       std::move(stability_metrics_provider));
@@ -287,6 +289,9 @@ void IOSChromeMetricsServiceClient::RegisterMetricsServiceProviders() {
   metrics_service_->RegisterMetricsProvider(CreateFileMetricsProvider(
       metrics_state_manager_->IsMetricsReportingEnabled()));
 
+  metrics_service_->RegisterMetricsProvider(
+        std::make_unique<metrics::EntropyStateProvider>(local_state));
+
   metrics_service_->RegisterMetricsProvider(
       std::make_unique<metrics::ScreenInfoMetricsProvider>());
 

ios/chrome/browser/metrics/ios_chrome_metrics_service_client_unittest.mm

@@ -95,7 +95,7 @@ TEST_F(IOSChromeMetricsServiceClientTest, TestRegisterMetricsServiceProviders) {
 
   // This is the number of metrics providers that are registered inside
   // IOSChromeMetricsServiceClient::Initialize().
-  expected_providers += 13;
+  expected_providers += 14;
 
   std::unique_ptr<IOSChromeMetricsServiceClient> chrome_metrics_service_client =
       IOSChromeMetricsServiceClient::Create(metrics_state_manager_.get());