[UKM] Support --force-enable-metrics-reporting flag in iOS

Bug: 828878
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I76115730b550c8320e05c7c9fc1a20dd129f3626
Reviewed-on: https://chromium-review.googlesource.com/1012748
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551469}

chrome/browser/metrics/chrome_metrics_service_client.cc

@@ -72,6 +72,7 @@
 #include "components/metrics/metrics_service.h"
 #include "components/metrics/metrics_service_client.h"
 #include "components/metrics/metrics_state_manager.h"
+#include "components/metrics/metrics_switches.h"
 #include "components/metrics/net/cellular_logic_helper.h"
 #include "components/metrics/net/net_metrics_log_uploader.h"
 #include "components/metrics/net/network_metrics_provider.h"
@@ -568,7 +569,7 @@ ChromeMetricsServiceClient::GetMetricsReportingDefaultState() {
 // static
 bool ChromeMetricsServiceClient::IsMetricsReportingForceEnabled() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kForceEnableMetricsReporting);
+      metrics::switches::kForceEnableMetricsReporting);
 }
 
 void ChromeMetricsServiceClient::Initialize() {

chrome/common/chrome_switches.cc

@@ -387,9 +387,6 @@ const char kForceAppMode[]                  = "force-app-mode";
 // is triggered.
 const char kForceDesktopIOSPromotion[] = "force-desktop-ios-promotion";
 
-// Forces metrics reporting to be enabled.
-const char kForceEnableMetricsReporting[] = "force-enable-metrics-reporting";
-
 // Displays the First Run experience when the browser is started, regardless of
 // whether or not it's actually the First Run (this overrides kNoFirstRun).
 const char kForceFirstRun[]                 = "force-first-run";

chrome/common/chrome_switches.h

@@ -122,7 +122,6 @@ extern const char kFastStart[];
 extern const char kForceAndroidAppMode[];
 extern const char kForceAppMode[];
 extern const char kForceDesktopIOSPromotion[];
-extern const char kForceEnableMetricsReporting[];
 extern const char kForceFirstRun[];
 extern const char kForceFirstRunDialog[];
 extern const char kForceLocalNtp[];

components/metrics/metrics_switches.cc

@@ -18,5 +18,8 @@ const char kMetricsRecordingOnly[] = "metrics-recording-only";
 // known as the Chrome Variations state.
 const char kResetVariationState[] = "reset-variation-state";
 
+// Forces metrics reporting to be enabled.
+const char kForceEnableMetricsReporting[] = "force-enable-metrics-reporting";
+
 }  // namespace switches
 }  // namespace metrics

components/metrics/metrics_switches.h

@@ -13,6 +13,7 @@ namespace switches {
 
 extern const char kMetricsRecordingOnly[];
 extern const char kResetVariationState[];
+extern const char kForceEnableMetricsReporting[];
 
 }  // namespace switches
 }  // namespace metrics

ios/chrome/browser/metrics/ios_chrome_metrics_service_client.h

@@ -56,6 +56,9 @@ class IOSChromeMetricsServiceClient : public IncognitoWebStateObserver,
   // Registers local state prefs used by this class.
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
+  // Checks if the user has forced metrics collection on via the override flag.
+  static bool IsMetricsReportingForceEnabled();
+
   // metrics::MetricsServiceClient:
   metrics::MetricsService* GetMetricsService() override;
   ukm::UkmService* GetUkmService() override;

ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm

@@ -29,6 +29,7 @@
 #include "components/metrics/metrics_pref_names.h"
 #include "components/metrics/metrics_reporting_default_state.h"
 #include "components/metrics/metrics_service.h"
+#include "components/metrics/metrics_switches.h"
 #include "components/metrics/net/cellular_logic_helper.h"
 #include "components/metrics/net/net_metrics_log_uploader.h"
 #include "components/metrics/net/network_metrics_provider.h"
@@ -99,6 +100,12 @@ void IOSChromeMetricsServiceClient::RegisterPrefs(
   ukm::UkmService::RegisterPrefs(registry);
 }
 
+// static
+bool IOSChromeMetricsServiceClient::IsMetricsReportingForceEnabled() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      metrics::switches::kForceEnableMetricsReporting);
+}
+
 metrics::MetricsService* IOSChromeMetricsServiceClient::GetMetricsService() {
   return metrics_service_.get();
 }
@@ -176,13 +183,14 @@ void IOSChromeMetricsServiceClient::Initialize() {
   metrics_service_ = std::make_unique<metrics::MetricsService>(
       metrics_state_manager_, this, local_state);
 
-  // Always restrict on iOS.
-  // TODO(crbug.com/828878): Use the flag to set this.
-  bool restrict_to_whitelist_entries = true;
-
-  if (base::FeatureList::IsEnabled(ukm::kUkmFeature))
+  if (IsMetricsReportingForceEnabled() ||
+      base::FeatureList::IsEnabled(ukm::kUkmFeature)) {
+    // We only need to restrict to whitelisted Entries if metrics reporting
+    // is not forced.
+    bool restrict_to_whitelist_entries = !IsMetricsReportingForceEnabled();
     ukm_service_ = std::make_unique<ukm::UkmService>(
         local_state, this, restrict_to_whitelist_entries);
+  }
 
   // Register metrics providers.
   metrics_service_->RegisterMetricsProvider(

ios/chrome/browser/metrics/ios_chrome_metrics_services_manager_client.h

@@ -41,12 +41,11 @@ class IOSChromeMetricsServicesManagerClient
       override;
   std::unique_ptr<const base::FieldTrial::EntropyProvider>
   CreateEntropyProvider() override;
-
   net::URLRequestContextGetter* GetURLRequestContext() override;
   bool IsMetricsReportingEnabled() override;
   bool IsMetricsConsentGiven() override;
-
   bool IsIncognitoSessionActive() override;
+  bool IsMetricsReportingForceEnabled() override;
 
   // Gets the MetricsStateManager, creating it if it has not already been
   // created.

ios/chrome/browser/metrics/ios_chrome_metrics_services_manager_client.mm

@@ -117,3 +117,7 @@ IOSChromeMetricsServicesManagerClient::GetMetricsStateManager() {
 bool IOSChromeMetricsServicesManagerClient::IsIncognitoSessionActive() {
   return TabModelList::IsOffTheRecordSessionActive();
 }
+
+bool IOSChromeMetricsServicesManagerClient::IsMetricsReportingForceEnabled() {
+  return IOSChromeMetricsServiceClient::IsMetricsReportingForceEnabled();
+}