Move Captive Portal Metrics logging behind a flag.

Metrics logged from the CaptivePortalMetricsTabHelper are useful to
determine the users affected by a broken connection due to a Captive
Portal. However, it is not necessary to log these metrics continuously.
Keeping the tab helper behind a flag allows re-enabling the metrics in
the future in order to examine the issues caused by Captive Portals.

Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I8c4fca02d85701ca1ef1b7bf0aec87cf08015bd0
Reviewed-on: https://chromium-review.googlesource.com/924571
Commit-Queue: Mike Dougherty <michaeldo@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537845}

ios/chrome/browser/about_flags.mm

@@ -150,6 +150,9 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
     {"ios-captive-portal", flag_descriptions::kCaptivePortalName,
      flag_descriptions::kCaptivePortalDescription, flags_ui::kOsIos,
      FEATURE_VALUE_TYPE(kCaptivePortalFeature)},
+    {"ios-captive-portal-metrics", flag_descriptions::kCaptivePortalMetricsName,
+     flag_descriptions::kCaptivePortalMetricsDescription, flags_ui::kOsIos,
+     FEATURE_VALUE_TYPE(kCaptivePortalMetrics)},
     {"in-product-help-demo-mode-choice",
      flag_descriptions::kInProductHelpDemoModeName,
      flag_descriptions::kInProductHelpDemoModeDescription, flags_ui::kOsIos,

ios/chrome/browser/ios_chrome_flag_descriptions.cc

@@ -20,6 +20,11 @@ const char kCaptivePortalDescription[] =
     "When enabled, the Captive Portal landing page will be displayed if it is "
     "detected that the user is connected to a Captive Portal network.";
 
+const char kCaptivePortalMetricsName[] = "Captive Portal Metrics";
+const char kCaptivePortalMetricsDescription[] =
+    "When enabled, some network issues will trigger a test to check if a "
+    "Captive Portal network is the cause of the issue.";
+
 const char kClippingTextfieldName[] = "Clipping Textfield";
 const char kClippingTextfieldDescription[] =
     "When enabled, the new URL clipping implementation compatible with iOS 11 "

ios/chrome/browser/ios_chrome_flag_descriptions.h

@@ -16,6 +16,10 @@ extern const char kBrowserTaskSchedulerDescription[];
 extern const char kCaptivePortalName[];
 extern const char kCaptivePortalDescription[];
 
+// Title and description for the flag to enable Captive Portal metrics logging.
+extern const char kCaptivePortalMetricsName[];
+extern const char kCaptivePortalMetricsDescription[];
+
 // Title and description for the flag to enable Omnibox Clipping.
 extern const char kClippingTextfieldName[];
 extern const char kClippingTextfieldDescription[];

ios/chrome/browser/ssl/captive_portal_features.cc

@@ -6,3 +6,6 @@
 
 const base::Feature kCaptivePortalFeature{"CaptivePortalFeature",
                                           base::FEATURE_ENABLED_BY_DEFAULT};
+
+const base::Feature kCaptivePortalMetrics{"CaptivePortalMetrics",
+                                          base::FEATURE_DISABLED_BY_DEFAULT};

ios/chrome/browser/ssl/captive_portal_features.h

@@ -10,4 +10,7 @@
 // Used to control the state of the Captive Portal Login feature.
 extern const base::Feature kCaptivePortalFeature;
 
+// Used to control the state of logging Captive Portal Metrics.
+extern const base::Feature kCaptivePortalMetrics;
+
 #endif  // IOS_CHROME_BROWSER_SSL_CAPTIVE_PORTAL_FEATURES_H_

ios/chrome/browser/tabs/BUILD.gn

@@ -109,6 +109,7 @@ source_set("tabs_internal") {
     "//ios/chrome/browser/sessions:serialisation",
     "//ios/chrome/browser/snapshots",
     "//ios/chrome/browser/ssl",
+    "//ios/chrome/browser/ssl:features",
     "//ios/chrome/browser/store_kit",
     "//ios/chrome/browser/sync",
     "//ios/chrome/browser/translate",

ios/chrome/browser/tabs/tab_helper_util.mm

@@ -8,6 +8,7 @@
 #error "This file requires ARC support."
 #endif
 
+#include "base/feature_list.h"
 #import "components/favicon/ios/web_favicon_driver.h"
 #include "components/history/core/browser/top_sites.h"
 #import "components/history/ios/browser/web_state_top_sites_observer.h"
@@ -28,6 +29,7 @@
 #import "ios/chrome/browser/reading_list/reading_list_web_state_observer.h"
 #import "ios/chrome/browser/sessions/ios_chrome_session_tab_helper.h"
 #import "ios/chrome/browser/snapshots/snapshot_tab_helper.h"
+#include "ios/chrome/browser/ssl/captive_portal_features.h"
 #import "ios/chrome/browser/ssl/captive_portal_metrics_tab_helper.h"
 #import "ios/chrome/browser/ssl/insecure_input_tab_helper.h"
 #import "ios/chrome/browser/ssl/ios_security_state_tab_helper.h"
@@ -77,7 +79,10 @@ void AttachTabHelpers(web::WebState* web_state, bool for_prerender) {
   StoreKitTabHelper::CreateForWebState(web_state);
   HistoryTabHelper::CreateForWebState(web_state);
   LoadTimingTabHelper::CreateForWebState(web_state);
-  CaptivePortalMetricsTabHelper::CreateForWebState(web_state);
+
+  if (base::FeatureList::IsEnabled(kCaptivePortalMetrics)) {
+    CaptivePortalMetricsTabHelper::CreateForWebState(web_state);
+  }
 
   ReadingListModel* model =
       ReadingListModelFactory::GetForBrowserState(browser_state);