Revert "Implement a site engagement backend for app banner triggering."

This reverts commit 02b30b18f74daf51b16b1b8ac733f9b44915137f.

Reason for revert: Speculative attempt to see if this fixes the FYI
memory bots (e.g. http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20Tests%20%28valgrind%29%283%29/builds/48940/steps/memory%20test%3A%20unit/logs/stdio)

NOTRY=true
TBR=benwells
NOTREECHECKS=true
BUG=553858

Review URL: https://codereview.chromium.org/1505633002

Cr-Commit-Position: refs/heads/master@{#363389}

12 files changed, 22 insertions, 257 deletions

diff --git a/chrome/browser/banners/app_banner_data_fetcher.cc b/chrome/browser/banners/app_banner_data_fetcher.cc
index 321e8d3..0090d10 100644
--- a/chrome/browser/banners/app_banner_data_fetcher.cc
+++ b/chrome/browser/banners/app_banner_data_fetcher.cc
@@ -188,9 +188,6 @@ void AppBannerDataFetcher::OnBannerPromptReply(
     return;
   }
 
-  AppBannerSettingsHelper::RecordMinutesFromFirstVisitToShow(
-      web_contents, validated_url_, GetAppIdentifier(), GetCurrentTime());
-
   // Definitely going to show the banner now.
   FOR_EACH_OBSERVER(Observer, observer_list_,
                     OnDecidedWhetherToShow(this, true));
diff --git a/chrome/browser/banners/app_banner_data_fetcher_browsertest.cc b/chrome/browser/banners/app_banner_data_fetcher_browsertest.cc
index c868268..b37df5f 100644
--- a/chrome/browser/banners/app_banner_data_fetcher_browsertest.cc
+++ b/chrome/browser/banners/app_banner_data_fetcher_browsertest.cc
@@ -9,10 +9,8 @@
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner.h"
-#include "base/test/histogram_tester.h"
 #include "base/thread_task_runner_handle.h"
 #include "chrome/browser/banners/app_banner_data_fetcher_desktop.h"
-#include "chrome/browser/banners/app_banner_metrics.h"
 #include "chrome/browser/banners/app_banner_settings_helper.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
@@ -99,7 +97,6 @@ class AppBannerDataFetcherBrowserTest : public InProcessBrowserTest,
                                         weak_factory_.GetWeakPtr(),
                                         128, 128));
 
-    base::HistogramTester histograms;
     base::RunLoop run_loop;
     quit_closure_ = run_loop.QuitClosure();
     scoped_ptr<TestObserver> observer(new TestObserver(fetcher.get(),
@@ -110,10 +107,6 @@ class AppBannerDataFetcherBrowserTest : public InProcessBrowserTest,
     EXPECT_EQ(expected_non_web_platform, non_web_platform_);
     EXPECT_EQ(expected_to_show, observer->will_show());
     ASSERT_FALSE(fetcher->is_active());
-
-    // If showing the banner, ensure that the minutes histogram is recorded.
-    histograms.ExpectTotalCount(banners::kMinutesHistogram,
-                                (observer->will_show() ? 1 : 0));
   }
 
   void RunBannerTest(const std::string& manifest_page,
diff --git a/chrome/browser/banners/app_banner_metrics.cc b/chrome/browser/banners/app_banner_metrics.cc
index f9bbd34..5ab6f59 100644
--- a/chrome/browser/banners/app_banner_metrics.cc
+++ b/chrome/browser/banners/app_banner_metrics.cc
@@ -4,48 +4,32 @@
 
 #include "chrome/browser/banners/app_banner_metrics.h"
 
-#include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 
 namespace banners {
 
-const char kDismissEventHistogram[] = "AppBanners.DismissEvent";
-const char kDisplayEventHistogram[] = "AppBanners.DisplayEvent";
-const char kInstallEventHistogram[] = "AppBanners.InstallEvent";
-const char kMinutesHistogram[] =
-    "AppBanners.MinutesFromFirstVisitToBannerShown";
-const char kUserResponseHistogram[] = "AppBanners.UserResponse";
-
 void TrackDismissEvent(int event) {
   DCHECK_LT(DISMISS_EVENT_MIN, event);
   DCHECK_LT(event, DISMISS_EVENT_MAX);
-  UMA_HISTOGRAM_SPARSE_SLOWLY(kDismissEventHistogram, event);
+  UMA_HISTOGRAM_SPARSE_SLOWLY("AppBanners.DismissEvent", event);
 }
 
 void TrackDisplayEvent(int event) {
   DCHECK_LT(DISPLAY_EVENT_MIN, event);
   DCHECK_LT(event, DISPLAY_EVENT_MAX);
-  UMA_HISTOGRAM_SPARSE_SLOWLY(kDisplayEventHistogram, event);
+  UMA_HISTOGRAM_SPARSE_SLOWLY("AppBanners.DisplayEvent", event);
 }
 
 void TrackInstallEvent(int event) {
   DCHECK_LT(INSTALL_EVENT_MIN, event);
   DCHECK_LT(event, INSTALL_EVENT_MAX);
-  UMA_HISTOGRAM_SPARSE_SLOWLY(kInstallEventHistogram, event);
-}
-
-void TrackMinutesFromFirstVisitToBannerShown(int minutes) {
-  // Histogram ranges from 1 minute to the number of minutes in 21 days.
-  // This is one more day than the decay length of time for site engagement,
-  // and seven more days than the expiry of visits for the app banner
-  // navigation heuristic.
-  UMA_HISTOGRAM_CUSTOM_COUNTS(kMinutesHistogram, minutes, 1, 30240, 100);
+  UMA_HISTOGRAM_SPARSE_SLOWLY("AppBanners.InstallEvent", event);
 }
 
 void TrackUserResponse(int event) {
   DCHECK_LT(USER_RESPONSE_MIN, event);
   DCHECK_LT(event, USER_RESPONSE_MAX);
-  UMA_HISTOGRAM_SPARSE_SLOWLY(kUserResponseHistogram, event);
+  UMA_HISTOGRAM_SPARSE_SLOWLY("AppBanners.UserResponse", event);
 }
 
 }  // namespace banners
diff --git a/chrome/browser/banners/app_banner_metrics.h b/chrome/browser/banners/app_banner_metrics.h
index 0b0939e..7c78179 100644
--- a/chrome/browser/banners/app_banner_metrics.h
+++ b/chrome/browser/banners/app_banner_metrics.h
@@ -57,16 +57,9 @@ enum UserResponse {
   USER_RESPONSE_MAX = 7,
 };
 
-extern const char kDismissEventHistogram[];
-extern const char kDisplayEventHistogram[];
-extern const char kInstallEventHistogram[];
-extern const char kMinutesHistogram[];
-extern const char kUserResponseHistogram[];
-
 void TrackDismissEvent(int event);
 void TrackDisplayEvent(int event);
 void TrackInstallEvent(int event);
-void TrackMinutesFromFirstVisitToBannerShown(int minutes);
 void TrackUserResponse(int event);
 
 };  // namespace banners
diff --git a/chrome/browser/banners/app_banner_settings_helper.cc b/chrome/browser/banners/app_banner_settings_helper.cc
index aca24f6..2f0bb43 100644
--- a/chrome/browser/banners/app_banner_settings_helper.cc
+++ b/chrome/browser/banners/app_banner_settings_helper.cc
@@ -8,14 +8,11 @@
 #include <string>
 
 #include "base/command_line.h"
-#include "base/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
-#include "base/strings/string_util.h"
 #include "chrome/browser/banners/app_banner_data_fetcher.h"
 #include "chrome/browser/banners/app_banner_metrics.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
-#include "chrome/browser/engagement/site_engagement_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
@@ -66,11 +63,9 @@ const char kBannerParamsDirectKey[] = "direct";
 const char kBannerParamsIndirectKey[] = "indirect";
 const char kBannerParamsTotalKey[] = "total";
 const char kBannerParamsMinutesKey[] = "minutes";
-const char kBannerSiteEngagementParamsKey[] = "app_banner_triggering";
-const char kBannerSiteEngagementParamsTotalKey[] =
-    "app_banner_triggering_total";
 
-// Total engagement score required before a banner will actually be triggered.
+// Total site engagements where a banner could have been shown before
+// a banner will actually be triggered.
 double gTotalEngagementToTrigger = 2;
 
 // Engagement weight assigned to direct and indirect navigations.
@@ -120,26 +115,10 @@ double GetEventEngagement(ui::PageTransition transition_type) {
   }
 }
 
-// Queries variations for the maximum site engagement score required to trigger
-// the banner showing.
-void UpdateSiteEngagementToTrigger() {
-  std::string total_param = variations::GetVariationParamValue(
-      SiteEngagementService::kEngagementParams,
-      kBannerSiteEngagementParamsTotalKey);
-
-  if (!total_param.empty()) {
-    double total_engagement = -1;
-
-    if (base::StringToDouble(total_param, &total_engagement) &&
-        total_engagement > 0) {
-      AppBannerSettingsHelper::SetTotalEngagementToTrigger(total_engagement);
-    }
-  }
-}
-
 // Queries variations for updates to the default engagement values assigned
 // to direct and indirect navigations.
 void UpdateEngagementWeights() {
+  std::map<std::string, std::string> params;
   std::string direct_param = variations::GetVariationParamValue(
       kBannerParamsKey, kBannerParamsDirectKey);
   std::string indirect_param = variations::GetVariationParamValue(
@@ -181,16 +160,6 @@ void UpdateMinutesBetweenVisits() {
   }
 }
 
-// Returns the site engagement karma score for the given origin URL under the
-// current profile.
-double GetSiteEngagementScoreForOrigin(
-    content::WebContents* web_contents,
-    const GURL& origin_url) {
-  SiteEngagementService* service = SiteEngagementService::Get(
-      Profile::FromBrowserContext(web_contents->GetBrowserContext()));
-  return service ? service->GetScore(origin_url) : 0;
-}
-
 }  // namespace
 
 void AppBannerSettingsHelper::ClearHistoryForURLs(
@@ -383,10 +352,6 @@ bool AppBannerSettingsHelper::ShouldShowBanner(
     return true;
   }
 
-  // Never show a banner when the package name or URL is empty.
-  if (package_name_or_start_url.empty())
-    return false;
-
   // Don't show if it has been added to the homescreen.
   base::Time added_time =
       GetSingleBannerEvent(web_contents, origin_url, package_name_or_start_url,
@@ -417,17 +382,14 @@ bool AppBannerSettingsHelper::ShouldShowBanner(
     return false;
   }
 
-  double total_engagement = 0;
-  if (ShouldUseSiteEngagementScore()) {
-    total_engagement =
-        GetSiteEngagementScoreForOrigin(web_contents, origin_url);
-  } else {
-    std::vector<BannerEvent> could_show_events = GetCouldShowBannerEvents(
-        web_contents, origin_url, package_name_or_start_url);
+  std::vector<BannerEvent> could_show_events = GetCouldShowBannerEvents(
+      web_contents, origin_url, package_name_or_start_url);
 
-    for (const auto& event : could_show_events)
-      total_engagement += event.engagement;
-  }
+  // Return true if the total engagement of each applicable could show event
+  // meets the trigger threshold.
+  double total_engagement = 0;
+  for (const auto& event : could_show_events)
+    total_engagement += event.engagement;
 
   if (total_engagement < gTotalEngagementToTrigger) {
     banners::TrackDisplayEvent(banners::DISPLAY_EVENT_NOT_VISITED_ENOUGH);
@@ -443,6 +405,8 @@ AppBannerSettingsHelper::GetCouldShowBannerEvents(
     const GURL& origin_url,
     const std::string& package_name_or_start_url) {
   std::vector<BannerEvent> result;
+  if (package_name_or_start_url.empty())
+    return result;
 
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
@@ -490,6 +454,9 @@ base::Time AppBannerSettingsHelper::GetSingleBannerEvent(
   DCHECK(event != APP_BANNER_EVENT_COULD_SHOW);
   DCHECK(event < APP_BANNER_EVENT_NUM_EVENTS);
 
+  if (package_name_or_start_url.empty())
+    return base::Time();
+
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
   HostContentSettingsMap* settings =
@@ -513,21 +480,6 @@ base::Time AppBannerSettingsHelper::GetSingleBannerEvent(
   return base::Time::FromInternalValue(internal_time);
 }
 
-void AppBannerSettingsHelper::RecordMinutesFromFirstVisitToShow(
-    content::WebContents* web_contents,
-    const GURL& origin_url,
-    const std::string& package_name_or_start_url,
-    base::Time time) {
-  std::vector<BannerEvent> could_show_events = GetCouldShowBannerEvents(
-      web_contents, origin_url, package_name_or_start_url);
-
-  int minutes = 0;
-  if (could_show_events.size())
-    minutes = (time - could_show_events[0].time).InMinutes();
-
-  banners::TrackMinutesFromFirstVisitToBannerShown(minutes);
-}
-
 void AppBannerSettingsHelper::SetEngagementWeights(double direct_engagement,
                                                    double indirect_engagement) {
   gDirectNavigationEngagement = direct_engagement;
@@ -571,32 +523,6 @@ base::Time AppBannerSettingsHelper::BucketTimeToResolution(
 }
 
 void AppBannerSettingsHelper::UpdateFromFieldTrial() {
-  // If we are using the site engagement score, only extract the total
-  // engagement to trigger from the params variations.
-  if (ShouldUseSiteEngagementScore()) {
-    UpdateSiteEngagementToTrigger();
-  } else {
-    UpdateEngagementWeights();
-    UpdateMinutesBetweenVisits();
-  }
-}
-
-bool AppBannerSettingsHelper::ShouldUseSiteEngagementScore() {
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnableSiteEngagementAppBanner)) {
-    return true;
-  }
-
-  // This experiment is controlled under the same key as the broader site
-  // engagement experiment rather than the banner experiment. This avoids cross
-  // pollution with other site engagement experiments. However, this experiment
-  // must only be active when there is one singular group under the banner
-  // experiment, otherwise the banner and site engagement banner experiments
-  // will conflict.
-  //
-  // Making the experiment active when a variations key is present allows us
-  // to have experiments which enable multiple features under site engagement.
-  std::string param = variations::GetVariationParamValue(
-      SiteEngagementService::kEngagementParams, kBannerSiteEngagementParamsKey);
-  return !param.empty();
+  UpdateEngagementWeights();
+  UpdateMinutesBetweenVisits();
 }
diff --git a/chrome/browser/banners/app_banner_settings_helper.h b/chrome/browser/banners/app_banner_settings_helper.h
index b46bc16..3ff877c 100644
--- a/chrome/browser/banners/app_banner_settings_helper.h
+++ b/chrome/browser/banners/app_banner_settings_helper.h
@@ -117,14 +117,6 @@ class AppBannerSettingsHelper {
       const std::string& package_name_or_start_url,
       AppBannerEvent event);
 
-  // Record a UMA statistic measuring the minutes between the first visit to the
-  // site and the first showing of the banner.
-  static void RecordMinutesFromFirstVisitToShow(
-      content::WebContents* web_contents,
-      const GURL& origin_url,
-      const std::string& package_name_or_start_url,
-      base::Time time);
-
   // Set the engagement weights assigned to direct and indirect navigations.
   static void SetEngagementWeights(double direct_engagement,
                                    double indirect_engagement);
@@ -145,10 +137,6 @@ class AppBannerSettingsHelper {
   // Updates all values from field trial.
   static void UpdateFromFieldTrial();
 
-  // Returns true if the app banner trigger condition should use the site
-  // engagement score instead of the navigation-based heuristic.
-  static bool ShouldUseSiteEngagementScore();
-
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AppBannerSettingsHelper);
 };
diff --git a/chrome/browser/banners/app_banner_settings_helper_unittest.cc b/chrome/browser/banners/app_banner_settings_helper_unittest.cc
index 254758a..82550f1 100644
--- a/chrome/browser/banners/app_banner_settings_helper_unittest.cc
+++ b/chrome/browser/banners/app_banner_settings_helper_unittest.cc
@@ -4,14 +4,8 @@
 
 #include <vector>
 
-#include "base/command_line.h"
-#include "chrome/browser/banners/app_banner_metrics.h"
 #include "chrome/browser/banners/app_banner_settings_helper.h"
-#include "chrome/browser/engagement/site_engagement_service.h"
-#include "chrome/browser/engagement/site_engagement_service_factory.h"
-#include "chrome/common/chrome_switches.h"
 #include "chrome/test/base/chrome_render_view_host_test_harness.h"
-#include "chrome/test/base/testing_profile.h"
 #include "ui/base/page_transition_types.h"
 
 namespace {
@@ -737,93 +731,3 @@ TEST_F(AppBannerSettingsHelperTest, OperatesOnOrigins) {
   EXPECT_TRUE(AppBannerSettingsHelper::ShouldShowBanner(
       web_contents(), url, kTestPackageName, reference_time));
 }
-
-TEST_F(AppBannerSettingsHelperTest, ShouldShowWithHigherTotal) {
-  AppBannerSettingsHelper::SetEngagementWeights(1, 1);
-  AppBannerSettingsHelper::SetTotalEngagementToTrigger(5);
-  GURL url(kTestURL);
-  NavigateAndCommit(url);
-
-  base::Time reference_time = GetReferenceTime();
-  base::Time second_day = reference_time + base::TimeDelta::FromDays(1);
-  base::Time third_day = reference_time + base::TimeDelta::FromDays(2);
-  base::Time fourth_day = reference_time + base::TimeDelta::FromDays(3);
-  base::Time fifth_day = reference_time + base::TimeDelta::FromDays(4);
-
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-
-  // It should take five visits to trigger the banner.
-  AppBannerSettingsHelper::RecordBannerCouldShowEvent(
-      web_contents(), url, kTestPackageName, reference_time,
-      ui::PAGE_TRANSITION_LINK);
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-
-  AppBannerSettingsHelper::RecordBannerCouldShowEvent(
-      web_contents(), url, kTestPackageName, second_day,
-      ui::PAGE_TRANSITION_TYPED);
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, second_day));
-
-  AppBannerSettingsHelper::RecordBannerCouldShowEvent(
-      web_contents(), url, kTestPackageName, third_day,
-      ui::PAGE_TRANSITION_GENERATED);
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, third_day));
-
-  AppBannerSettingsHelper::RecordBannerCouldShowEvent(
-      web_contents(), url, kTestPackageName, fourth_day,
-      ui::PAGE_TRANSITION_LINK);
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, fourth_day));
-
-  // Visit the site again; now it should be shown.
-  AppBannerSettingsHelper::RecordBannerCouldShowEvent(
-      web_contents(), url, kTestPackageName, fifth_day,
-      ui::PAGE_TRANSITION_TYPED);
-  EXPECT_TRUE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, fifth_day));
-}
-
-// Test that the banner triggers correctly using site engagement.
-TEST_F(AppBannerSettingsHelperTest, SiteEngagementTrigger) {
-  AppBannerSettingsHelper::SetTotalEngagementToTrigger(2);
-  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-  command_line->AppendSwitch(switches::kEnableSiteEngagementAppBanner);
-
-  SiteEngagementService* service =
-      SiteEngagementServiceFactory::GetForProfile(profile());
-  DCHECK(service);
-
-  // Not used, but needed for method call.
-  base::Time reference_time = GetReferenceTime();
-  GURL url(kTestURL);
-
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-
-  service->AddPoints(url, 1);
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-
-  service->AddPoints(url, 1);
-  EXPECT_TRUE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-
-  AppBannerSettingsHelper::SetTotalEngagementToTrigger(5);
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-
-  service->AddPoints(url, 1.5);
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-
-  service->AddPoints(url, 0.5);
-  EXPECT_FALSE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-
-  service->AddPoints(url, 1.5);
-  EXPECT_TRUE(AppBannerSettingsHelper::ShouldShowBanner(
-      web_contents(), url, kTestPackageName, reference_time));
-}
diff --git a/chrome/browser/engagement/site_engagement_service.cc b/chrome/browser/engagement/site_engagement_service.cc
index 52cbaf0..b875eb6 100644
--- a/chrome/browser/engagement/site_engagement_service.cc
+++ b/chrome/browser/engagement/site_engagement_service.cc
@@ -15,7 +15,6 @@
 #include "base/time/clock.h"
 #include "base/time/default_clock.h"
 #include "base/values.h"
-#include "chrome/browser/banners/app_banner_settings_helper.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/engagement/site_engagement_eviction_policy.h"
 #include "chrome/browser/engagement/site_engagement_helper.h"
@@ -282,8 +281,7 @@ bool SiteEngagementService::IsEnabled() {
   // return true immediately.
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableSiteEngagementService) ||
-      SiteEngagementEvictionPolicy::IsEnabled() ||
-      AppBannerSettingsHelper::ShouldUseSiteEngagementScore()) {
+      SiteEngagementEvictionPolicy::IsEnabled()) {
     return true;
   }
 
diff --git a/chrome/browser/engagement/site_engagement_service.h b/chrome/browser/engagement/site_engagement_service.h
index 46bf989..6489fff 100644
--- a/chrome/browser/engagement/site_engagement_service.h
+++ b/chrome/browser/engagement/site_engagement_service.h
@@ -180,7 +180,6 @@ class SiteEngagementService : public KeyedService,
   FRIEND_TEST_ALL_PREFIXES(SiteEngagementServiceTest, GetTotalUserInputPoints);
   FRIEND_TEST_ALL_PREFIXES(SiteEngagementServiceTest,
                            CleanupOriginsOnHistoryDeletion);
-  FRIEND_TEST_ALL_PREFIXES(AppBannerSettingsHelperTest, SiteEngagementTrigger);
 
   // Only used in tests.
   SiteEngagementService(Profile* profile, scoped_ptr<base::Clock> clock);
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index f71178a..9443ec0 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -520,12 +520,6 @@ const char kEnableSimplifiedFullscreenUI[]  = "enable-simplified-fullscreen-ui";
 const char kDisableSimplifiedFullscreenUI[] =
     "disable-simplified-fullscreen-ui";
 
-// Enable the Site Engagement App Banner which triggers app install banners
-// using the site engagement service rather than a navigation-based heuristic.
-// Implicitly enables the site engagement service.
-const char kEnableSiteEngagementAppBanner[] =
-    "enable-site-engagement-app-banner";
-
 // Enable the Site Engagement Eviction Policy which evicts temporary storage
 // using the site engagement service. Implicitly enables the site engagement
 // service.
diff --git a/chrome/common/chrome_switches.h b/chrome/common/chrome_switches.h
index 67908f2..6a4e48f 100644
--- a/chrome/common/chrome_switches.h
+++ b/chrome/common/chrome_switches.h
@@ -150,7 +150,6 @@ extern const char kEnableSettingsWindow[];
 extern const char kDisableSettingsWindow[];
 extern const char kEnableSimplifiedFullscreenUI[];
 extern const char kDisableSimplifiedFullscreenUI[];
-extern const char kEnableSiteEngagementAppBanner[];
 extern const char kEnableSiteEngagementEvictionPolicy[];
 extern const char kEnableSiteEngagementService[];
 extern const char kEnableSupervisedUserManagedBookmarksFolder[];
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index dacd572..389e013 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -367,16 +367,6 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
-<histogram name="AppBanners.MinutesFromFirstVisitToBannerShown" units="minutes">
-  <owner>dominickn@chromium.org</owner>
-  <summary>
-    App banners promote an application related to the current website, and are
-    requested specifically through the current page's HTML.  This stat tracks
-    the number of minutes between the first recorded visit to an origin and the
-    time when the banner is actually shown.
-  </summary>
-</histogram>
-
 <histogram name="AppBanners.UserResponse" enum="AppBannersUserResponse">
   <owner>dominickn@chromium.org</owner>
   <summary>