[Metrics] Record UMA for number of installed apps and extensions

This CL adds 9 UMA histogram metrics for the number of installed apps
and extensions. At most once a day and when the user signs out, the
number of recently used apps is summed up in a snapshot and uploaded
to UMA. This CL also reports the number of installed and enabled
non-component browser extensions and themes, regardless of when they
were last used.

Bug: 1110557
Change-Id: Ia0b7c180581b040fe77929d545ae46383576afca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2350543
Commit-Queue: Toby Huang <tobyhuang@chromium.org>
Reviewed-by: Aga Wronska <agawronska@chromium.org>
Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816870}

chrome/browser/chromeos/BUILD.gn

@@ -917,6 +917,8 @@ source_set("chromeos") {
     "child_accounts/event_based_status_reporting_service_factory.h",
     "child_accounts/family_features.cc",
     "child_accounts/family_features.h",
+    "child_accounts/family_user_app_metrics.cc",
+    "child_accounts/family_user_app_metrics.h",
     "child_accounts/family_user_metrics_service.cc",
     "child_accounts/family_user_metrics_service.h",
     "child_accounts/family_user_metrics_service_factory.cc",
@@ -3254,6 +3256,7 @@ source_set("unit_tests") {
     "certificate_provider/certificate_provider_service_unittest.cc",
     "child_accounts/child_user_service_unittest.cc",
     "child_accounts/event_based_status_reporting_service_unittest.cc",
+    "child_accounts/family_user_app_metrics_unittest.cc",
     "child_accounts/family_user_metrics_service_unittest.cc",
     "child_accounts/family_user_session_metrics_unittest.cc",
     "child_accounts/parent_access_code/authenticator_unittest.cc",

chrome/browser/chromeos/child_accounts/family_user_app_metrics.cc

@@ -0,0 +1,156 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/chromeos/child_accounts/family_user_app_metrics.h"
+
+#include <memory>
+
+#include "base/logging.h"
+#include "base/metrics/histogram_functions.h"
+#include "base/time/time.h"
+#include "chrome/browser/apps/app_service/app_service_proxy.h"
+#include "chrome/browser/apps/app_service/app_service_proxy_factory.h"
+#include "chrome/browser/profiles/profile.h"
+#include "components/services/app_service/public/cpp/app_registry_cache.h"
+#include "components/services/app_service/public/mojom/types.mojom.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/common/extension.h"
+#include "extensions/common/extension_set.h"
+#include "extensions/common/manifest.h"
+
+namespace chromeos {
+
+namespace {
+constexpr base::TimeDelta k28Days = base::TimeDelta::FromDays(28);
+}  // namespace
+
+// static
+// UMA metrics for a snapshot count of installed and enabled extensions for a
+// given family user.
+const char FamilyUserAppMetrics::kInstalledExtensionsCountHistogramName[] =
+    "FamilyUser.InstalledExtensionsCount";
+const char FamilyUserAppMetrics::kEnabledExtensionsCountHistogramName[] =
+    "FamilyUser.EnabledExtensionsCount";
+
+// UMA metrics for a snapshot count of installed apps for a given family user.
+const char FamilyUserAppMetrics::kOtherAppsCountHistogramName[] =
+    "FamilyUser.OtherAppsCount";
+const char FamilyUserAppMetrics::kArcAppsCountHistogramName[] =
+    "FamilyUser.ArcAppsCount";
+const char FamilyUserAppMetrics::kBorealisAppsCountHistogramName[] =
+    "FamilyUser.BorealisAppsCount";
+const char FamilyUserAppMetrics::kCrostiniAppsCountHistogramName[] =
+    "FamilyUser.CrostiniAppsCount";
+const char FamilyUserAppMetrics::kExtensionAppsCountHistogramName[] =
+    "FamilyUser.ExtensionAppsCount";
+const char FamilyUserAppMetrics::kWebAppsCountHistogramName[] =
+    "FamilyUser.WebAppsCount";
+// Sum of the above.
+const char FamilyUserAppMetrics::kTotalAppsCountHistogramName[] =
+    "FamilyUser.TotalAppsCount";
+
+FamilyUserAppMetrics::FamilyUserAppMetrics(Profile* profile)
+    : extension_registry_(extensions::ExtensionRegistry::Get(profile)),
+      app_registry_(&apps::AppServiceProxyFactory::GetForProfile(profile)
+                         ->AppRegistryCache()) {
+  DCHECK(extension_registry_);
+  DCHECK(app_registry_);
+}
+
+FamilyUserAppMetrics::~FamilyUserAppMetrics() {
+  if (on_new_day_) {
+    RecordInstalledExtensionsCount();
+    RecordEnabledExtensionsCount();
+    RecordRecentlyUsedAppsCount();
+  }
+}
+
+void FamilyUserAppMetrics::OnNewDay() {
+  on_new_day_ = true;
+}
+
+void FamilyUserAppMetrics::RecordInstalledExtensionsCount() {
+  int counter = 0;
+  std::unique_ptr<extensions::ExtensionSet> all_installed_extensions =
+      extension_registry_->GenerateInstalledExtensionsSet();
+  for (const auto& extension : *all_installed_extensions) {
+    if (extensions::Manifest::IsComponentLocation(extension->location()))
+      continue;
+    if (extension->is_extension() || extension->is_theme())
+      counter++;
+  }
+  // If a family user has more than a thousand extensions installed, then that
+  // count is going into an overflow bucket. We don't expect this scenario to
+  // happen often.
+  base::UmaHistogramCounts1000(kInstalledExtensionsCountHistogramName, counter);
+}
+
+void FamilyUserAppMetrics::RecordEnabledExtensionsCount() {
+  int counter = 0;
+  for (const auto& extension : extension_registry_->enabled_extensions()) {
+    if (extensions::Manifest::IsComponentLocation(extension->location()))
+      continue;
+    if (extension->is_extension() || extension->is_theme())
+      counter++;
+  }
+  // If a family user has more than a thousand extensions enabled, then that
+  // count is going into an overflow bucket. We don't expect this scenario to
+  // happen often.
+  base::UmaHistogramCounts1000(kEnabledExtensionsCountHistogramName, counter);
+}
+
+void FamilyUserAppMetrics::RecordRecentlyUsedAppsCount() {
+  int other_counter, arc_counter, borealis_counter, crostini_counter,
+      extension_counter, web_counter, total_counter;
+  other_counter = arc_counter = borealis_counter = crostini_counter =
+      extension_counter = web_counter = total_counter = 0;
+  app_registry_->ForEachApp([&other_counter, &arc_counter, &borealis_counter,
+                             &crostini_counter, &extension_counter,
+                             &web_counter,
+                             &total_counter](const apps::AppUpdate& update) {
+    // Only count apps that have been used recently.
+    if (base::Time::Now() - update.LastLaunchTime() > k28Days)
+      return;
+    switch (update.AppType()) {
+      case apps::mojom::AppType::kArc:
+        arc_counter++;
+        break;
+      case apps::mojom::AppType::kBorealis:
+        borealis_counter++;
+        break;
+      case apps::mojom::AppType::kCrostini:
+        crostini_counter++;
+        break;
+      case apps::mojom::AppType::kExtension:
+        // The InstalledExtensionsCount only includes regular browser
+        // extensions and themes. This counter only includes apps. The two
+        // counters are mutually exclusive.
+        extension_counter++;
+        break;
+      case apps::mojom::AppType::kWeb:
+        web_counter++;
+        break;
+      default:
+        // We're not interested in tracking other app types in detail.
+        other_counter++;
+        break;
+    }
+    total_counter++;
+  });
+  // If a family user has more than a thousand apps installed, then that count
+  // is going into an overflow bucket. We don't expect this scenario to happen
+  // often.
+  base::UmaHistogramCounts1000(kOtherAppsCountHistogramName, other_counter);
+  base::UmaHistogramCounts1000(kArcAppsCountHistogramName, arc_counter);
+  base::UmaHistogramCounts1000(kBorealisAppsCountHistogramName,
+                               borealis_counter);
+  base::UmaHistogramCounts1000(kCrostiniAppsCountHistogramName,
+                               crostini_counter);
+  base::UmaHistogramCounts1000(kExtensionAppsCountHistogramName,
+                               extension_counter);
+  base::UmaHistogramCounts1000(kWebAppsCountHistogramName, web_counter);
+  base::UmaHistogramCounts1000(kTotalAppsCountHistogramName, total_counter);
+}
+
+}  // namespace chromeos

chrome/browser/chromeos/child_accounts/family_user_app_metrics.h

@@ -0,0 +1,67 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_CHROMEOS_CHILD_ACCOUNTS_FAMILY_USER_APP_METRICS_H_
+#define CHROME_BROWSER_CHROMEOS_CHILD_ACCOUNTS_FAMILY_USER_APP_METRICS_H_
+
+#include "chrome/browser/chromeos/child_accounts/family_user_metrics_service.h"
+
+class Profile;
+
+namespace extensions {
+class ExtensionRegistry;
+}  // namespace extensions
+
+namespace apps {
+class AppRegistryCache;
+}  // namespace apps
+
+namespace chromeos {
+
+class FamilyUserAppMetrics : public FamilyUserMetricsService::Observer {
+ public:
+  // UMA metrics for a snapshot count of installed and enabled extensions for a
+  // given family user.
+  static const char kInstalledExtensionsCountHistogramName[];
+  static const char kEnabledExtensionsCountHistogramName[];
+
+  // UMA metrics for a snapshot count of recently used apps for a given family
+  // user.
+  static const char kOtherAppsCountHistogramName[];
+  static const char kArcAppsCountHistogramName[];
+  static const char kBorealisAppsCountHistogramName[];
+  static const char kCrostiniAppsCountHistogramName[];
+  static const char kExtensionAppsCountHistogramName[];
+  static const char kWebAppsCountHistogramName[];
+  // Sum of the above metrics for a given snapshot.
+  static const char kTotalAppsCountHistogramName[];
+
+  explicit FamilyUserAppMetrics(Profile* profile);
+  FamilyUserAppMetrics(const FamilyUserAppMetrics&) = delete;
+  FamilyUserAppMetrics& operator=(const FamilyUserAppMetrics&) = delete;
+  ~FamilyUserAppMetrics() override;
+
+ private:
+  // FamilyUserMetricsService::Observer:
+  void OnNewDay() override;
+
+  // Records the number of non-component extensions that the family user has
+  // installed. This count is a superset of the enabled extensions count.
+  void RecordInstalledExtensionsCount();
+
+  // Records the number of non-component extensions that the family user has
+  // enabled. This count is a subset of the installed extensions count.
+  void RecordEnabledExtensionsCount();
+
+  // Records the number of apps that the family user has recently used.
+  void RecordRecentlyUsedAppsCount();
+
+  const extensions::ExtensionRegistry* const extension_registry_;
+  apps::AppRegistryCache* const app_registry_;
+
+  bool on_new_day_ = false;
+};
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_CHILD_ACCOUNTS_FAMILY_USER_APP_METRICS_H_