Add NotebookLM flag to ChromeOS preinstalled web apps

This adds a flag (disabled) to control whether we preinstall
NotebookLM on ChromeOS devices.
This CL also makes some minor improvements to about flag documentation.

Bug: b:402986247
Change-Id: Idc96249539af70ca4d607b0877e2c86e55f8cb6a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6367996
Reviewed-by: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Sophia Lin <sophialin@google.com>
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1437291}

ash/constants/web_app_id_constants.h

@@ -121,6 +121,10 @@ inline constexpr char kGraduationAppId[] = "dcmgllglecpogfcjmdkdncendnjphdcd";
 //     "chrome://help-app/"))
 inline constexpr char kHelpAppId[] = "nbljnnecbjbmifnoehiemkgefbnpoeak";
 
+// Generated as: web_app::GenerateAppId(/*manifest_id=*/std::nullopt, GURL(
+//     "https://notebooklm.google.com/"))
+inline constexpr char kNotebookLmAppId[] = "gjcmcplpgihbecacndmmbaenpfgimlec";
+
 // Generated as: web_app::GenerateAppId(/*manifest_id=*/std::nullopt, GURL(
 //     "chrome://media-app/"))
 inline constexpr char kMediaAppId[] = "jhdjimmaggjajfjphpljagpgkidjilnj";

chrome/browser/about_flags.cc

@@ -11926,6 +11926,15 @@ const FeatureEntry kFeatureEntries[] = {
 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_MAC) || BUILDFLAG(IS_WIN) ||
         // BUILDFLAG(IS_CHROME_OS)
 
+#if BUILDFLAG(IS_CHROMEOS)
+    {"notebook-lm-app-preinstall",
+     flag_descriptions::kNotebookLmAppPreinstallName,
+     flag_descriptions::kNotebookLmAppPreinstallDescription, kOsCrOS,
+     FEATURE_VALUE_TYPE(chromeos::features::kNotebookLmAppPreinstall)},
+#endif  // BUILDFLAG(IS_CHROMEOS)
+
+    // Add new entries above this line.
+
     // NOTE: Adding a new flag requires adding a corresponding entry to enum
     // "LoginCustomFlags" in tools/metrics/histograms/enums.xml. See "Flag
     // Histograms" in tools/metrics/histograms/README.md (run the

chrome/browser/ash/extensions/default_app_order.cc

@@ -146,6 +146,8 @@ void GetDefault(std::vector<std::string>* app_ids) {
 
     ash::kMessagesAppId,
 
+    ash::kNotebookLmAppId,
+
     arc::kYoutubeAppId,
     extension_misc::kYoutubeAppId,
     ash::kYoutubeAppId,

chrome/browser/flag-metadata.json

@@ -6259,6 +6259,11 @@
     ],
     "expiry_milestone": 145
   },
+  {
+    "name": "notebook-lm-app-preinstall",
+    "owners": [ "alancutter@google.com", "crosdev-commerce-eng@google.com" ],
+    "expiry_milestone": 146
+  },
   {
     "name": "notification-collision-management",
     "owners": [ "thegreenfrog@chromium.org", "bling-gsu-pod@google.com" ],

chrome/browser/flag_descriptions.cc

@@ -2593,6 +2593,10 @@ const char kNewEtc1EncoderDescription[] =
     "thumbnails.";
 #endif
 
+const char kNotebookLmAppPreinstallName[] = "NotebookLM app preload";
+const char kNotebookLmAppPreinstallDescription[] =
+    "Preloads the NotebookLM app.";
+
 const char kNotificationSchedulerName[] = "Notification scheduler";
 const char kNotificationSchedulerDescription[] =
     "Enable notification scheduler feature.";

chrome/browser/flag_descriptions.h

@@ -1489,6 +1489,9 @@ extern const char kNewEtc1EncoderName[];
 extern const char kNewEtc1EncoderDescription[];
 #endif
 
+extern const char kNotebookLmAppPreinstallName[];
+extern const char kNotebookLmAppPreinstallDescription[];
+
 extern const char kNotificationSchedulerName[];
 extern const char kNotificationSchedulerDescription[];
 

chrome/browser/web_applications/BUILD.gn

@@ -586,6 +586,8 @@ source_set("web_applications") {
         "preinstalled_web_apps/google_meet.h",
         "preinstalled_web_apps/messages_dogfood.cc",
         "preinstalled_web_apps/messages_dogfood.h",
+        "preinstalled_web_apps/notebook_lm.cc",
+        "preinstalled_web_apps/notebook_lm.h",
       ]
     }
 

chrome/browser/web_applications/preinstalled_app_install_features.cc

@@ -44,26 +44,19 @@ constexpr const std::string_view kShippedPreinstalledAppInstallFeatures[] = {
 
 bool g_always_enabled_for_testing = false;
 
-struct FeatureWithEnabledFunction {
-  raw_ref<const base::Feature> feature;
-  bool (*enabled_func)();
-};
-
 // A hard coded list of features available for externally installed apps to
-// gate their installation on via their config file settings. Each feature has a
-// function to run to determine whether it is enabled. See |kFeatureName| in
-// preinstalled_web_app_utils.h.
+// gate their installation on via their config file settings. See |kFeatureName|
+// in preinstalled_web_app_utils.h.
 //
 // After a feature flag has been shipped and should be cleaned up, move it into
 // kShippedPreinstalledAppInstallFeatures to ensure any external installation
 // configs that reference it continue to see it as enabled.
-constexpr const FeatureWithEnabledFunction
-    kPreinstalledAppInstallFeaturesWithEnabledFunctions[] = {
+constexpr const raw_ref<const base::Feature> kPreinstalledAppInstallFeatures[] =
+    {
 #if BUILDFLAG(IS_CHROMEOS)
-        {raw_ref(chromeos::features::kCloudGamingDevice),
-         &chromeos::features::IsCloudGamingDeviceEnabled},
-        {raw_ref(chromeos::features::kGeminiAppPreinstall),
-         &chromeos::features::IsGeminiAppPreinstallEnabled}
+        raw_ref(chromeos::features::kCloudGamingDevice),
+        raw_ref(chromeos::features::kGeminiAppPreinstall),
+        raw_ref(chromeos::features::kNotebookLmAppPreinstall),
 #endif
 };
 
@@ -108,10 +101,10 @@ bool IsPreinstalledAppInstallFeatureEnabled(std::string_view feature_name) {
     }
   }
 
-  for (const auto& feature_with_function :
-       kPreinstalledAppInstallFeaturesWithEnabledFunctions) {
-    if (feature_with_function.feature->name == feature_name) {
-      return feature_with_function.enabled_func();
+  for (const raw_ref<const base::Feature> feature :
+       kPreinstalledAppInstallFeatures) {
+    if (feature->name == feature_name) {
+      return base::FeatureList::IsEnabled(*feature);
     }
   }
 

chrome/browser/web_applications/preinstalled_web_apps/notebook_lm.cc

@@ -0,0 +1,35 @@
+// Copyright 2025 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/web_applications/preinstalled_web_apps/notebook_lm.h"
+
+#include <memory>
+
+#include "ash/constants/web_app_id_constants.h"
+#include "chrome/browser/apps/user_type_filter.h"
+#include "chrome/browser/web_applications/external_install_options.h"
+#include "chrome/browser/web_applications/mojom/user_display_mode.mojom.h"
+#include "chrome/browser/web_applications/web_app_constants.h"
+#include "chromeos/constants/chromeos_features.h"
+#include "url/gurl.h"
+
+namespace web_app {
+
+ExternalInstallOptions GetConfigForNotebookLm() {
+  static constexpr char kUrl[] = "https://notebooklm.google.com/install";
+  ExternalInstallOptions options(
+      /*install_url=*/GURL(kUrl),
+      /*user_display_mode=*/mojom::UserDisplayMode::kStandalone,
+      /*install_source=*/ExternalInstallSource::kExternalDefault);
+  options.add_to_applications_menu = true;
+  options.add_to_search = true;
+  options.expected_app_id = ash::kNotebookLmAppId;
+  options.gate_on_feature = chromeos::features::kNotebookLmAppPreinstall.name;
+  options.is_preferred_app_for_supported_links = true;
+  options.user_type_allowlist = {apps::kUserTypeUnmanaged};
+
+  return options;
+}
+
+}  // namespace web_app

chrome/browser/web_applications/preinstalled_web_apps/notebook_lm.h

@@ -0,0 +1,17 @@
+// Copyright 2025 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_WEB_APPLICATIONS_PREINSTALLED_WEB_APPS_NOTEBOOK_LM_H_
+#define CHROME_BROWSER_WEB_APPLICATIONS_PREINSTALLED_WEB_APPS_NOTEBOOK_LM_H_
+
+#include "chrome/browser/web_applications/external_install_options.h"
+
+namespace web_app {
+
+// Returns the config for preinstalling the NotebookLm app.
+ExternalInstallOptions GetConfigForNotebookLm();
+
+}  // namespace web_app
+
+#endif  // CHROME_BROWSER_WEB_APPLICATIONS_PREINSTALLED_WEB_APPS_NOTEBOOK_LM_H_

chrome/browser/web_applications/preinstalled_web_apps/preinstalled_web_apps.cc

@@ -37,6 +37,7 @@
 #include "chrome/browser/web_applications/preinstalled_web_apps/google_calendar.h"
 #include "chrome/browser/web_applications/preinstalled_web_apps/google_meet.h"
 #include "chrome/browser/web_applications/preinstalled_web_apps/messages_dogfood.h"
+#include "chrome/browser/web_applications/preinstalled_web_apps/notebook_lm.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "extensions/common/constants.h"
 #include "google_apis/gaia/gaia_auth_util.h"
@@ -98,6 +99,7 @@ std::vector<ExternalInstallOptions> GetChromeBrandedApps(
 #if BUILDFLAG(IS_CHROMEOS)
       GetConfigForCalculator(),
       GetConfigForGemini(device_info),
+      GetConfigForNotebookLm(),
       GetConfigForGoogleCalendar(),
       GetConfigForGoogleChat(/*is_standalone=*/true,
                              /*only_for_new_users=*/false),

chromeos/constants/chromeos_features.cc

@@ -160,6 +160,11 @@ BASE_FEATURE(kMahiSummarizeSelected,
              "MahiSummarizeSelected",
              base::FEATURE_ENABLED_BY_DEFAULT);
 
+// Controls whether NotebookLM is preinstalled.
+BASE_FEATURE(kNotebookLmAppPreinstall,
+             "NotebookLmAppPreinstall",
+             base::FEATURE_DISABLED_BY_DEFAULT);
+
 // Kill switch to disable the new guest profile implementation on CrOS that is
 // consistent with desktop chrome.
 // TODO(crbug.com/40233408): Remove if the change is fully launched.

chromeos/constants/chromeos_features.h

@@ -76,6 +76,8 @@ BASE_DECLARE_FEATURE(kFeatureManagementDisableChromeCompose);
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 BASE_DECLARE_FEATURE(kFeatureManagementRoundedWindows);
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
+BASE_DECLARE_FEATURE(kNotebookLmAppPreinstall);
+COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 BASE_DECLARE_FEATURE(kNewGuestProfile);
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 BASE_DECLARE_FEATURE(kNotificationWidthIncrease);

docs/how_to_add_your_feature_flag.md

@@ -105,7 +105,7 @@ for WebView flags.
 
 You have to modify these five files in total.
 
-* [chrome/browser/about_flags.cc](https://cs.chromium.org/chromium/src/chrome/browser/about_flags.cc) (Add your changes at the bottom of the list)
+* [chrome/browser/about_flags.cc](https://cs.chromium.org/chromium/src/chrome/browser/about_flags.cc) (Add your changes at the bottom of the list, search for "Add new entries above this line.")
 * [chrome/browser/flag_descriptions.cc](https://cs.chromium.org/chromium/src/chrome/browser/flag_descriptions.cc) (Features should be alphabetically sorted)
 * [chrome/browser/flag_descriptions.h](https://cs.chromium.org/chromium/src/chrome/browser/flag_descriptions.h) (Features should be alphabetically sorted)
 * [tools/metrics/histograms/enums.xml](https://cs.chromium.org/chromium/src/tools/metrics/histograms/enums.xml)

tools/metrics/histograms/enums.xml

@@ -12133,6 +12133,7 @@ from previous Chrome versions.
   <int value="-792079435" label="EnableAppsGridGapFeature:disabled"/>
   <int value="-791916053" label="FriendlierErrorDialog:disabled"/>
   <int value="-791778534" label="LauncherQueryHighlighting:enabled"/>
+  <int value="-791730714" label="NotebookLmAppPreinstall:disabled"/>
   <int value="-791590673" label="bookmarks-tree-view:enabled"/>
   <int value="-790900615" label="NtpShoppingTasksModule:disabled"/>
   <int value="-790544721"
@@ -14370,6 +14371,7 @@ from previous Chrome versions.
   <int value="86582659" label="enable-extension-ai-data-collection"/>
   <int value="86900696" label="SanitizerAPIv0:enabled"/>
   <int value="87306743" label="VariationsFakeCrashAfterStartup:disabled"/>
+  <int value="88127181" label="NotebookLmAppPreinstall:enabled"/>
   <int value="88437020" label="FeaturePolicy:enabled"/>
   <int value="88863813" label="DesktopPWAsDetailedInstallDialog:enabled"/>
   <int value="89036875" label="DeferRendererTasksAfterInput:disabled"/>