Migrate to NOTREACHED() in extensions/

NOTREACHED() and NOTREACHED_IN_MIGRATION() are both CHECK-fatal now.
The former is [[noreturn]] so this CL also performs dead-code removal
after the NOTREACHED().

This CL does not attempt to do additional rewrites of any surrounding
code, like:

if (!foo) {
  NOTREACHED();
}

to CHECK(foo);

Those transforms take a non-trivial amount of time (and there are
thousands of instances). Cleanup can be left as an exercise for the
reader.

Bug: 40580068
Change-Id: I80696f361f79908132f9a0e3d8654592f2e37c13
Low-Coverage-Reason: OTHER Should-be-unreachable code
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5951563
Commit-Queue: Peter Boström <pbos@chromium.org>
Reviewed-by: Emilia Paz <emiliapaz@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1371865}

extensions/browser/activity.cc

@@ -46,8 +46,7 @@ const char* Activity::ToString(Type type) {
     case DEBUGGER:
       return "DEBUGGER";
   }
-  NOTREACHED_IN_MIGRATION();
-  return "";
+  NOTREACHED();
 }
 
 }  // namespace extensions

extensions/browser/api/app_current_window_internal/app_current_window_internal_api.cc

@@ -57,8 +57,6 @@ const char kRequiresFramelessWindow[] =
 const char kAlwaysOnTopPermission[] =
     "The \"app.window.alwaysOnTop\" permission is required.";
 
-const char kInvalidParameters[] = "Invalid parameters.";
-
 const int kUnboundedSize = SizeConstraints::kUnboundedSize;
 
 void GetBoundsFields(const Bounds& bounds_spec, gfx::Rect* bounds) {
@@ -206,8 +204,7 @@ AppCurrentWindowInternalSetBoundsFunction::Run() {
 
   bounds::BoundsType bounds_type = bounds::GetBoundsType(params->bounds_type);
   if (bounds_type == bounds::INVALID_TYPE) {
-    NOTREACHED_IN_MIGRATION();
-    return RespondNow(Error(kInvalidParameters));
+    NOTREACHED();
   }
 
   // Start with the current bounds, and change any values that are specified in
@@ -245,7 +242,7 @@ AppCurrentWindowInternalSetBoundsFunction::Run() {
       break;
     }
     case bounds::INVALID_TYPE:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
 
   if (original_window_bounds != window_bounds) {
@@ -276,8 +273,7 @@ AppCurrentWindowInternalSetSizeConstraintsFunction::Run() {
   bounds::BoundsType bounds_type = bounds::GetBoundsType(params->bounds_type);
   if (bounds_type != bounds::INNER_BOUNDS &&
       bounds_type != bounds::OUTER_BOUNDS) {
-    NOTREACHED_IN_MIGRATION();
-    return RespondNow(Error(kInvalidParameters));
+    NOTREACHED();
   }
 
   gfx::Size original_min_size =

extensions/browser/api/audio/audio_device_id_calculator.cc

@@ -43,8 +43,7 @@ void AudioDeviceIdCalculator::LoadStableIdMap() {
   for (size_t i = 0; i < ids_list.size(); ++i) {
     const std::string* audio_service_stable_id = ids_list[i].GetIfString();
     if (!audio_service_stable_id) {
-      NOTREACHED_IN_MIGRATION() << "Non string stable device ID.";
-      continue;
+      NOTREACHED() << "Non string stable device ID.";
     }
     stable_id_map_[*audio_service_stable_id] = base::NumberToString(i);
   }

extensions/browser/api/audio/audio_service_chromeos.cc

@@ -64,8 +64,7 @@ api::audio::DeviceType GetAsAudioApiDeviceType(AudioDeviceType type) {
       return api::audio::DeviceType::kOther;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return api::audio::DeviceType::kOther;
+  NOTREACHED();
 }
 
 }  // namespace

extensions/browser/api/audio/audio_service_utils.cc

@@ -18,8 +18,7 @@ api::audio::StreamType ConvertStreamTypeFromMojom(
     case crosapi::mojom::StreamType::kOutput:
       return api::audio::StreamType::kOutput;
   }
-  NOTREACHED_IN_MIGRATION();
-  return api::audio::StreamType::kNone;
+  NOTREACHED();
 }
 
 crosapi::mojom::StreamType ConvertStreamTypeToMojom(
@@ -32,8 +31,7 @@ crosapi::mojom::StreamType ConvertStreamTypeToMojom(
     case api::audio::StreamType::kOutput:
       return crosapi::mojom::StreamType::kOutput;
   }
-  NOTREACHED_IN_MIGRATION();
-  return crosapi::mojom::StreamType::kNone;
+  NOTREACHED();
 }
 
 api::audio::DeviceType ConvertDeviceTypeFromMojom(
@@ -74,8 +72,7 @@ api::audio::DeviceType ConvertDeviceTypeFromMojom(
     case crosapi::mojom::DeviceType::kOther:
       return api::audio::DeviceType::kOther;
   }
-  NOTREACHED_IN_MIGRATION();
-  return api::audio::DeviceType::kNone;
+  NOTREACHED();
 }
 
 crosapi::mojom::DeviceType ConvertDeviceTypeToMojom(
@@ -116,8 +113,7 @@ crosapi::mojom::DeviceType ConvertDeviceTypeToMojom(
     case api::audio::DeviceType::kOther:
       return crosapi::mojom::DeviceType::kOther;
   }
-  NOTREACHED_IN_MIGRATION();
-  return crosapi::mojom::DeviceType::kNone;
+  NOTREACHED();
 }
 
 std::unique_ptr<api::audio::DeviceFilter> ConvertDeviceFilterFromMojom(

extensions/browser/api/bluetooth/bluetooth_api_utils.cc

@@ -197,7 +197,7 @@ device::BluetoothFilterType ToBluetoothDeviceFilterType(FilterType type) {
     case FilterType::kKnown:
       return device::BluetoothFilterType::KNOWN;
     default:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
 }
 #endif

extensions/browser/api/bluetooth/bluetooth_private_api.cc

@@ -176,8 +176,7 @@ bt_private::ConnectResultType DeviceConnectErrorToConnectResult(
     case device::BluetoothDevice::ERROR_SOCKET:
       return bt_private::ConnectResultType::kSocketError;
     case device::BluetoothDevice::NUM_CONNECT_ERROR_CODES:
-      NOTREACHED_IN_MIGRATION();
-      break;
+      NOTREACHED();
   }
   return bt_private::ConnectResultType::kNone;
 }
@@ -446,7 +445,7 @@ void BluetoothPrivateSetPairingResponseFunction::DoWork(
         device->CancelPairing();
         break;
       default:
-        NOTREACHED_IN_MIGRATION();
+        NOTREACHED();
     }
   }
 

extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_api.cc

@@ -139,12 +139,10 @@ std::string StatusToString(BluetoothLowEnergyEventRouter::Status status) {
     case BluetoothLowEnergyEventRouter::kStatusErrorWakelock:
       return kErrorWakelock;
     case BluetoothLowEnergyEventRouter::kStatusSuccess:
-      NOTREACHED_IN_MIGRATION();
-      break;
+      NOTREACHED();
     default:
       return kErrorOperationFailed;
   }
-  return "";
 }
 
 extensions::BluetoothLowEnergyEventRouter* GetEventRouter(

extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.cc

@@ -255,12 +255,9 @@ DeviceConnectErrorCodeToStatus(BluetoothDevice::ConnectErrorCode error_code) {
     case device::BluetoothDevice::ConnectErrorCode::ERROR_SOCKET:
       return extensions::BluetoothLowEnergyEventRouter::kStatusErrorSocket;
     case BluetoothDevice::NUM_CONNECT_ERROR_CODES:
-      NOTREACHED_IN_MIGRATION();
-      return extensions::BluetoothLowEnergyEventRouter::
-          kStatusErrorInvalidArguments;
+      NOTREACHED();
   }
-  NOTREACHED_IN_MIGRATION();
-  return extensions::BluetoothLowEnergyEventRouter::kStatusErrorFailed;
+  NOTREACHED();
 }
 
 }  // namespace

extensions/browser/api/clipboard/clipboard_api.cc

@@ -102,7 +102,7 @@ bool ClipboardSetImageDataFunction::IsAdditionalItemsParamValid(
         has_text_html = true;
         break;
       default:
-        NOTREACHED_IN_MIGRATION();
+        NOTREACHED();
     }
     // Check maximum length of the string data.
     if (item.data.length() > max_item_data_bytes)

extensions/browser/api/content_settings/content_settings_helpers.cc

@@ -25,8 +25,7 @@ std::string GetDefaultPort(const std::string& scheme) {
     return "80";
   if (scheme == url::kHttpsScheme)
     return "443";
-  NOTREACHED_IN_MIGRATION();
-  return std::string();
+  NOTREACHED();
 }
 
 }  // namespace

extensions/browser/api/content_settings/content_settings_store.cc

@@ -311,8 +311,7 @@ const OriginValueMap* ContentSettingsStore::GetValueMap(
       return &entry->settings;
     case ChromeSettingScope::kRegularOnly:
       // TODO(bauerb): Implement regular-only content settings.
-      NOTREACHED_IN_MIGRATION();
-      return nullptr;
+      NOTREACHED();
     case ChromeSettingScope::kIncognitoPersistent:
       return &entry->incognito_persistent_settings;
     case ChromeSettingScope::kIncognitoSessionOnly:
@@ -321,8 +320,7 @@ const OriginValueMap* ContentSettingsStore::GetValueMap(
       break;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return nullptr;
+  NOTREACHED();
 }
 
 void ContentSettingsStore::ClearContentSettingsForExtension(

extensions/browser/api/declarative/declarative_api.cc

@@ -235,8 +235,7 @@ void EventsEventAddRulesFunction::RecordUMA(
       type = kDeclarativeWebRequestWebviewAddRules;
       break;
     case DeclarativeAPIType::kUnknown:
-      NOTREACHED_IN_MIGRATION();
-      return;
+      NOTREACHED();
   }
   RecordUMAHelper(type);
 }
@@ -276,8 +275,7 @@ void EventsEventRemoveRulesFunction::RecordUMA(
       type = kDeclarativeWebRequestWebviewRemoveRules;
       break;
     case DeclarativeAPIType::kUnknown:
-      NOTREACHED_IN_MIGRATION();
-      return;
+      NOTREACHED();
   }
   RecordUMAHelper(type);
 }
@@ -321,8 +319,7 @@ void EventsEventGetRulesFunction::RecordUMA(
       type = kDeclarativeWebRequestWebviewGetRules;
       break;
     case DeclarativeAPIType::kUnknown:
-      NOTREACHED_IN_MIGRATION();
-      return;
+      NOTREACHED();
   }
   RecordUMAHelper(type);
 }

extensions/browser/api/declarative_net_request/extension_url_pattern_index_matcher.cc

@@ -174,7 +174,7 @@ std::optional<RequestAction> ExtensionUrlPatternIndexMatcher::GetActionHelper(
     case flat::ActionType_allow_all_requests:
     case flat::ActionType_modify_headers:
     case flat::ActionType_count:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
 
   return std::nullopt;
@@ -230,8 +230,7 @@ ExtensionUrlPatternIndexMatcher::GetMatchersForStage(
       return headers_received_matchers_;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return before_request_matchers_;
+  NOTREACHED();
 }
 
 void ExtensionUrlPatternIndexMatcher::SetDisabledRuleIds(

extensions/browser/api/declarative_net_request/file_sequence_helper.cc

@@ -161,8 +161,7 @@ UpdateDynamicRulesStatus GetUpdateDynamicRuleStatus(LoadRulesetResult result) {
       break;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return UpdateDynamicRulesStatus::kSuccess;
+  NOTREACHED();
 }
 
 // Helper to create the new list of dynamic rules. Returns false on failure and

extensions/browser/api/declarative_net_request/flat_ruleset_indexer.cc

@@ -471,8 +471,7 @@ FlatRulesetIndexer::GetBuilders(const IndexedRule& indexed_rule) {
     case dnr_api::RuleActionType::kNone:
       break;
   }
-  NOTREACHED_IN_MIGRATION();
-  return {};
+  NOTREACHED();
 }
 
 }  // namespace extensions::declarative_net_request

extensions/browser/api/declarative_net_request/indexed_rule.cc

@@ -438,8 +438,7 @@ uint8_t GetActionTypePriority(dnr_api::RuleActionType action_type) {
     case dnr_api::RuleActionType::kNone:
       break;
   }
-  NOTREACHED_IN_MIGRATION();
-  return 0;
+  NOTREACHED();
 }
 
 void RecordLargeRegexUMA(bool is_large_regex) {

extensions/browser/api/declarative_net_request/regex_rules_matcher.cc

@@ -74,7 +74,7 @@ bool ActionTypeAllowsMultipleActions(flat::ActionType action_type) {
     case flat::ActionType_modify_headers:
       return true;
     case flat::ActionType_count:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
   return true;
 }
@@ -356,8 +356,7 @@ std::optional<RequestAction> RegexRulesMatcher::CreateActionFromInfo(
       return CreateAllowAllRequestsAction(params, rule);
     case flat::ActionType_modify_headers:
     case flat::ActionType_count:
-      NOTREACHED_IN_MIGRATION();
-      break;
+      NOTREACHED();
   }
 
   return std::nullopt;
@@ -410,8 +409,7 @@ const RegexRulesMatcher::MatchHelper& RegexRulesMatcher::GetMatcherForStage(
       return headers_received_matcher_;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return before_request_matcher_;
+  NOTREACHED();
 }
 
 }  // namespace extensions::declarative_net_request

extensions/browser/api/declarative_net_request/ruleset_manager.cc

@@ -329,8 +329,7 @@ std::optional<RequestAction> RulesetManager::GetAction(
       case RequestAction::Type::ALLOW_ALL_REQUESTS:
         return 1;
       case RequestAction::Type::MODIFY_HEADERS:
-        NOTREACHED_IN_MIGRATION();
-        return 0;
+        NOTREACHED();
     }
   };
 

extensions/browser/api/declarative_net_request/ruleset_matcher.cc

@@ -372,8 +372,7 @@ size_t RulesetMatcher::GetRulesCount(RulesetMatchingStage stage) const {
              regex_matcher_.GetHeadersReceivedRulesCount();
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return 0u;
+  NOTREACHED();
 }
 
 size_t RulesetMatcher::GetRegexRulesCount(RulesetMatchingStage stage) const {
@@ -384,8 +383,7 @@ size_t RulesetMatcher::GetRegexRulesCount(RulesetMatchingStage stage) const {
       return regex_matcher_.GetHeadersReceivedRulesCount();
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return 0u;
+  NOTREACHED();
 }
 
 }  // namespace extensions::declarative_net_request

extensions/browser/api/declarative_net_request/utils.cc

@@ -228,8 +228,7 @@ dnr_api::ResourceType GetDNRResourceType(WebRequestResourceType resource_type) {
     case WebRequestResourceType::WEBBUNDLE:
       return dnr_api::ResourceType::kWebbundle;
   }
-  NOTREACHED_IN_MIGRATION();
-  return dnr_api::ResourceType::kOther;
+  NOTREACHED();
 }
 
 // Maps dnr_api::ResourceType to WebRequestResourceType.
@@ -267,11 +266,9 @@ WebRequestResourceType GetWebRequestResourceType(
     case dnr_api::ResourceType::kWebbundle:
       return WebRequestResourceType::WEBBUNDLE;
     case dnr_api::ResourceType::kNone:
-      NOTREACHED_IN_MIGRATION();
-      return WebRequestResourceType::OTHER;
+      NOTREACHED();
   }
-  NOTREACHED_IN_MIGRATION();
-  return WebRequestResourceType::OTHER;
+  NOTREACHED();
 }
 
 dnr_api::RequestDetails CreateRequestDetails(const WebRequestInfo& request) {
@@ -339,8 +336,7 @@ flat::ActionType ConvertToFlatActionType(dnr_api::RuleActionType action_type) {
     case dnr_api::RuleActionType::kNone:
       break;
   }
-  NOTREACHED_IN_MIGRATION();
-  return flat::ActionType_block;
+  NOTREACHED();
 }
 
 std::string GetPublicRulesetID(const Extension& extension,
@@ -720,8 +716,7 @@ std::string GetParseError(ParseResult error_reason, int rule_id) {
           kErrorResponseHeaderRuleCannotModifyRequestHeaders,
           base::NumberToString(rule_id));
   }
-  NOTREACHED_IN_MIGRATION();
-  return std::string();
+  NOTREACHED();
 }
 
 flat_rule::ElementType GetElementType(WebRequestResourceType web_request_type) {
@@ -757,8 +752,7 @@ flat_rule::ElementType GetElementType(WebRequestResourceType web_request_type) {
     case WebRequestResourceType::WEB_TRANSPORT:
       return flat_rule::ElementType_WEBTRANSPORT;
   }
-  NOTREACHED_IN_MIGRATION();
-  return flat_rule::ElementType_OTHER;
+  NOTREACHED();
 }
 
 flat_rule::ElementType GetElementType(dnr_api::ResourceType resource_type) {
@@ -796,8 +790,7 @@ flat_rule::ElementType GetElementType(dnr_api::ResourceType resource_type) {
     case dnr_api::ResourceType::kOther:
       return flat_rule::ElementType_OTHER;
   }
-  NOTREACHED_IN_MIGRATION();
-  return flat_rule::ElementType_NONE;
+  NOTREACHED();
 }
 
 // Maps an HTTP request method string to flat_rule::RequestMethod.
@@ -841,8 +834,7 @@ flat_rule::RequestMethod GetRequestMethod(
     dnr_api::RequestMethod request_method) {
   switch (request_method) {
     case dnr_api::RequestMethod::kNone:
-      NOTREACHED_IN_MIGRATION();
-      return flat_rule::RequestMethod_NONE;
+      NOTREACHED();
     case dnr_api::RequestMethod::kConnect:
       return flat_rule::RequestMethod_CONNECT;
     case dnr_api::RequestMethod::kDelete:
@@ -862,8 +854,7 @@ flat_rule::RequestMethod GetRequestMethod(
     case dnr_api::RequestMethod::kPut:
       return flat_rule::RequestMethod_PUT;
   }
-  NOTREACHED_IN_MIGRATION();
-  return flat_rule::RequestMethod_NONE;
+  NOTREACHED();
 }
 
 flat_rule::RequestMethod GetRequestMethod(

extensions/browser/api/declarative_webrequest/webrequest_action.cc

@@ -1000,8 +1000,7 @@ std::string WebRequestRequestCookieAction::GetName() const {
     case helpers::REMOVE:
       return keys::kRemoveRequestCookieType;
   }
-  NOTREACHED_IN_MIGRATION();
-  return "";
+  NOTREACHED();
 }
 
 std::optional<EventResponseDelta> WebRequestRequestCookieAction::CreateDelta(
@@ -1048,8 +1047,7 @@ std::string WebRequestResponseCookieAction::GetName() const {
     case helpers::REMOVE:
       return keys::kRemoveResponseCookieType;
   }
-  NOTREACHED_IN_MIGRATION();
-  return "";
+  NOTREACHED();
 }
 
 std::optional<EventResponseDelta> WebRequestResponseCookieAction::CreateDelta(

extensions/browser/api/declarative_webrequest/webrequest_condition_attribute.cc

@@ -428,8 +428,7 @@ bool HeaderMatcher::StringMatchTest::Matches(
       }
   }
   // We never get past the "switch", but the compiler worries about no return.
-  NOTREACHED_IN_MIGRATION();
-  return false;
+  NOTREACHED();
 }
 
 HeaderMatcher::StringMatchTest::StringMatchTest(const std::string& data,
@@ -480,9 +479,7 @@ HeaderMatcher::HeaderMatchTest::Create(const base::Value::Dict& tests) {
     } else if (entry.first == keys::kValueEqualsKey) {
       match_type = StringMatchTest::kEquals;
     } else {
-      NOTREACHED_IN_MIGRATION();  // JSON schema type checking should prevent
-                                  // this.
-      return nullptr;
+      NOTREACHED();  // JSON schema type checking should prevent this.
     }
     const base::Value* content = &entry.second;
 
@@ -503,9 +500,7 @@ HeaderMatcher::HeaderMatchTest::Create(const base::Value::Dict& tests) {
         break;
       }
       default: {
-        NOTREACHED_IN_MIGRATION();  // JSON schema type checking should prevent
-                                    // this.
-        return nullptr;
+        NOTREACHED();  // JSON schema type checking should prevent this.
       }
     }
   }
@@ -735,8 +730,7 @@ bool ParseListOfStages(const base::Value& value, int* out_stages) {
     } else if (stage_name == keys::kOnAuthRequiredEnum) {
       stages |= ON_AUTH_REQUIRED;
     } else {
-      NOTREACHED_IN_MIGRATION();  // JSON schema checks prevent getting here.
-      return false;
+      NOTREACHED();  // JSON schema checks prevent getting here.
     }
   }
 

extensions/browser/api/declarative_webrequest/webrequest_condition_attribute_unittest.cc

@@ -273,8 +273,7 @@ base::Value::Dict GetDictFromArray(
           entry->GetList().Append(*value);
           break;
         default:
-          NOTREACHED_IN_MIGRATION();  // We never put other Values here.
-          return base::Value::Dict();
+          NOTREACHED();  // We never put other Values here.
       }
     } else {
       dict.Set(*name, *value);

extensions/browser/api/device_permissions_manager.cc

@@ -83,8 +83,7 @@ const char* TypeToString(DevicePermissionEntry::Type type) {
     case DevicePermissionEntry::Type::HID:
       return kDeviceTypeHid;
   }
-  NOTREACHED_IN_MIGRATION();
-  return "";
+  NOTREACHED();
 }
 
 // Persists a DevicePermissionEntry in ExtensionPrefs.
@@ -603,7 +602,7 @@ void DevicePermissionsManager::RemoveEntry(
   } else if (entry->type_ == DevicePermissionEntry::Type::HID) {
     device_permissions->ephemeral_hid_devices_.erase(entry->device_guid_);
   } else {
-    NOTREACHED_IN_MIGRATION();
+    NOTREACHED();
   }
 }
 

extensions/browser/api/feedback_private/feedback_private_api.cc

@@ -374,9 +374,7 @@ ExtensionFunction::ResponseAction FeedbackPrivateReadLogSourceFunction::Run() {
 
   return RespondLater();
 #else
-  NOTREACHED_IN_MIGRATION()
-      << "API function is not supported on this platform.";
-  return RespondNow(Error("API function is not supported on this platform."));
+  NOTREACHED() << "API function is not supported on this platform.";
 #endif  // BUILDFLAG(IS_CHROMEOS)
 }
 

extensions/browser/api/guest_view/web_view/web_view_internal_api.cc

@@ -426,9 +426,8 @@ std::string WebViewInternalCaptureVisibleRegionFunction::GetErrorMessage(
       reason_description = "screenshot has been disabled";
       break;
     case OK:
-      NOTREACHED_IN_MIGRATION()
+      NOTREACHED()
           << "GetErrorMessage should not be called with a successful result";
-      return "";
   }
   return ErrorUtils::FormatErrorMessage("Failed to capture webview: *",
                                         reason_description);
@@ -534,8 +533,7 @@ bool WebViewInternalExecuteCodeFunction::LoadFileForEmbedder(
 
   switch (host_id().type) {
     case mojom::HostID::HostType::kExtensions:
-      NOTREACHED_IN_MIGRATION();
-      return false;
+      NOTREACHED();
     case mojom::HostID::HostType::kControlledFrameEmbedder:
       url_fetcher_ = std::make_unique<ControlledFrameEmbedderURLFetcher>(
           source_process_id(), render_frame_host()->GetRoutingID(), file_url,
@@ -774,7 +772,7 @@ ExtensionFunction::ResponseAction WebViewInternalSetZoomModeFunction::Run() {
       zoom_mode = ZoomController::ZOOM_MODE_DISABLED;
       break;
     default:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
 
   GetGuest().SetZoomMode(zoom_mode);
@@ -804,7 +802,7 @@ ExtensionFunction::ResponseAction WebViewInternalGetZoomModeFunction::Run() {
       zoom_mode = web_view_internal::ZoomMode::kDisabled;
       break;
     default:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
 
   return RespondNow(WithArguments(web_view_internal::ToString(zoom_mode)));
@@ -982,7 +980,7 @@ ExtensionFunction::ResponseAction WebViewInternalSetPermissionFunction::Run() {
     case api::web_view_internal::SetPermissionAction::kDefault:
       break;
     default:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
 
   std::string user_input;

extensions/browser/api/lock_screen_data/lock_screen_data_api.cc

@@ -23,8 +23,7 @@ std::string GetErrorString(lock_screen_data::OperationResult result) {
   switch (result) {
     case lock_screen_data::OperationResult::kSuccess:
     case lock_screen_data::OperationResult::kCount:
-      NOTREACHED_IN_MIGRATION() << "Expected a failure code.";
-      return "Unknown";
+      NOTREACHED() << "Expected a failure code.";
     case lock_screen_data::OperationResult::kFailed:
       return "Unknown";
     case lock_screen_data::OperationResult::kInvalidKey:
@@ -36,8 +35,7 @@ std::string GetErrorString(lock_screen_data::OperationResult result) {
     case lock_screen_data::OperationResult::kUnknownExtension:
       return "Not found";
   }
-  NOTREACHED_IN_MIGRATION() << "Unknown operation status";
-  return "Unknown";
+  NOTREACHED() << "Unknown operation status";
 }
 
 }  // namespace

extensions/browser/api/lock_screen_data/lock_screen_item_storage.cc

@@ -308,8 +308,7 @@ bool LockScreenItemStorage::IsContextAllowed(content::BrowserContext* context) {
     case SessionLockedState::kNotLocked:
       return context_ == context;
   }
-  NOTREACHED_IN_MIGRATION() << "Unknown session locked state";
-  return false;
+  NOTREACHED() << "Unknown session locked state";
 }
 
 void LockScreenItemStorage::CreateItemImpl(const ExtensionId& extension_id,

extensions/browser/api/management/management_api.cc

@@ -255,7 +255,7 @@ management::ExtensionInfo CreateExtensionInfo(
         break;
       case LAUNCH_TYPE_INVALID:
       case NUM_LAUNCH_TYPES:
-        NOTREACHED_IN_MIGRATION();
+        NOTREACHED();
     }
 
     info.available_launch_types = GetAvailableLaunchTypes(extension, delegate);
@@ -997,7 +997,7 @@ ExtensionFunction::ResponseAction ManagementSetLaunchTypeFunction::Run() {
       launch_type = LAUNCH_TYPE_WINDOW;
       break;
     case management::LaunchType::kNone:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
 
   delegate->SetLaunchType(browser_context(), params->id, launch_type);

extensions/browser/api/media_perception_private/conversion_utils.cc

@@ -28,8 +28,7 @@ HotwordType HotwordTypeProtoToIdl(const mri::HotwordDetection::Type& type) {
     case mri::HotwordDetection::OK_GOOGLE:
       return HotwordType::kOkGoogle;
   }
-  NOTREACHED_IN_MIGRATION() << "Unknown hotword type: " << type;
-  return HotwordType::kUnknownType;
+  NOTREACHED() << "Unknown hotword type: " << type;
 }
 
 Hotword HotwordProtoToIdl(const mri::HotwordDetection::Hotword& hotword) {
@@ -159,8 +158,7 @@ LightCondition LightConditionProtoToIdl(
     case mri::VideoHumanPresenceDetection::BLACK_FRAME:
       return LightCondition::kBlackFrame;
     default:
-      NOTREACHED_IN_MIGRATION() << "Unknown light condition: " << condition;
-      return LightCondition::kUnspecified;
+      NOTREACHED() << "Unknown light condition: " << condition;
   }
 }
 
@@ -262,7 +260,7 @@ DistanceUnits DistanceUnitsProtoToIdl(const mri::Distance& distance) {
       case mri::Distance::UNITS_UNSPECIFIED:
         return DistanceUnits::kUnspecified;
     }
-    NOTREACHED_IN_MIGRATION() << "Unknown distance units: " << distance.units();
+    NOTREACHED() << "Unknown distance units: " << distance.units();
   }
   return DistanceUnits::kUnspecified;
 }
@@ -288,8 +286,7 @@ FramePerceptionType FramePerceptionTypeProtoToIdl(int type) {
     case mri::FramePerception::MOTION_DETECTION:
       return FramePerceptionType::kMotionDetection;
   }
-  NOTREACHED_IN_MIGRATION() << "Unknown frame perception type: " << type;
-  return FramePerceptionType::kUnknownType;
+  NOTREACHED() << "Unknown frame perception type: " << type;
 }
 
 EntityType EntityTypeProtoToIdl(const mri::Entity& entity) {
@@ -306,7 +303,7 @@ EntityType EntityTypeProtoToIdl(const mri::Entity& entity) {
       case mri::Entity::UNSPECIFIED:
         return EntityType::kUnspecified;
     }
-    NOTREACHED_IN_MIGRATION() << "Unknown entity type: " << entity.type();
+    NOTREACHED() << "Unknown entity type: " << entity.type();
   }
   return EntityType::kUnspecified;
 }
@@ -403,8 +400,7 @@ ImageFormat ImageFormatProtoToIdl(const mri::ImageFrame& image_frame) {
       case mri::ImageFrame::FORMAT_UNSPECIFIED:
         return ImageFormat::kNone;
     }
-    NOTREACHED_IN_MIGRATION()
-        << "Unknown image format: " << image_frame.format();
+    NOTREACHED() << "Unknown image format: " << image_frame.format();
   }
   return ImageFormat::kNone;
 }
@@ -474,8 +470,7 @@ Status StateStatusProtoToIdl(const mri::State& state) {
     case mri::State::STATUS_UNSPECIFIED:
       return Status::kNone;
   }
-  NOTREACHED_IN_MIGRATION() << "Reached status not in switch.";
-  return Status::kNone;
+  NOTREACHED() << "Reached status not in switch.";
 }
 
 mri::State::Status StateStatusIdlToProto(const State& state) {
@@ -496,8 +491,7 @@ mri::State::Status StateStatusIdlToProto(const State& state) {
     case Status::kNone:
       return mri::State::STATUS_UNSPECIFIED;
   }
-  NOTREACHED_IN_MIGRATION() << "Reached status not in switch.";
-  return mri::State::STATUS_UNSPECIFIED;
+  NOTREACHED() << "Reached status not in switch.";
 }
 
 Feature FeatureProtoToIdl(int feature) {
@@ -515,8 +509,7 @@ Feature FeatureProtoToIdl(int feature) {
     case mri::State::FEATURE_UNSET:
       return Feature::kNone;
   }
-  NOTREACHED_IN_MIGRATION() << "Reached feature not in switch.";
-  return Feature::kNone;
+  NOTREACHED() << "Reached feature not in switch.";
 }
 
 mri::State::Feature FeatureIdlToProto(const Feature& feature) {
@@ -534,8 +527,7 @@ mri::State::Feature FeatureIdlToProto(const Feature& feature) {
     case Feature::kNone:
       return mri::State::FEATURE_UNSET;
   }
-  NOTREACHED_IN_MIGRATION() << "Reached feature not in switch.";
-  return mri::State::FEATURE_UNSET;
+  NOTREACHED() << "Reached feature not in switch.";
 }
 
 base::Value NamedTemplateArgumentValueProtoToValue(
@@ -548,9 +540,8 @@ base::Value NamedTemplateArgumentValueProtoToValue(
     case mri::State::NamedTemplateArgument::ValueCase::VALUE_NOT_SET:
       return base::Value();
   }
-  NOTREACHED_IN_MIGRATION() << "Unknown NamedTemplateArgument::ValueCase "
-                            << named_template_argument.value_case();
-  return base::Value();
+  NOTREACHED() << "Unknown NamedTemplateArgument::ValueCase "
+               << named_template_argument.value_case();
 }
 
 bool NamedTemplateArgumentProtoToIdl(
@@ -585,9 +576,8 @@ mri::State::NamedTemplateArgument NamedTemplateArgumentIdlToProto(
       named_template_argument_proto.set_num(
           *named_template_argument.value->as_number);
     } else {
-      NOTREACHED_IN_MIGRATION()
-          << "Failed to convert NamedTemplateARgument::Value IDL to "
-             "Proto, unkown value type.";
+      NOTREACHED() << "Failed to convert NamedTemplateARgument::Value IDL to "
+                      "Proto, unkown value type.";
     }
   }
 

extensions/browser/api/messaging/extension_message_port.cc

@@ -714,8 +714,7 @@ bool ExtensionMessagePort::IsServiceWorkerActivity(
       return is_for_onetime_channel() || should_have_strong_keepalive();
     default:
       // Extension message port should not check for other activity types.
-      NOTREACHED_IN_MIGRATION();
-      return false;
+      NOTREACHED();
   }
 }
 

extensions/browser/api/messaging/message_service.cc

@@ -1077,8 +1077,7 @@ void MessageService::OnOpenChannelAllowed(
 
   auto pending_for_incognito = pending_incognito_channels_.find(channel_id);
   if (pending_for_incognito == pending_incognito_channels_.end()) {
-    NOTREACHED_IN_MIGRATION();
-    return;
+    NOTREACHED();
   }
   PendingMessagesQueue pending_messages;
   pending_messages.swap(pending_for_incognito->second);

extensions/browser/api/networking_private/networking_private_delegate.cc

@@ -18,14 +18,12 @@ NetworkingPrivateDelegate::~NetworkingPrivateDelegate() = default;
 
 void NetworkingPrivateDelegate::AddObserver(
     NetworkingPrivateDelegateObserver* observer) {
-  NOTREACHED_IN_MIGRATION()
-      << "Class does not use NetworkingPrivateDelegateObserver";
+  NOTREACHED() << "Class does not use NetworkingPrivateDelegateObserver";
 }
 
 void NetworkingPrivateDelegate::RemoveObserver(
     NetworkingPrivateDelegateObserver* observer) {
-  NOTREACHED_IN_MIGRATION()
-      << "Class does not use NetworkingPrivateDelegateObserver";
+  NOTREACHED() << "Class does not use NetworkingPrivateDelegateObserver";
 }
 
 void NetworkingPrivateDelegate::StartActivate(

extensions/browser/api/networking_private/networking_private_delegate_factory.cc

@@ -70,15 +70,17 @@ NetworkingPrivateDelegateFactory::BuildServiceInstanceForBrowserContext(
   delegate =
       std::make_unique<NetworkingPrivateServiceClient>(std::move(wifi_service));
 #else
-  NOTREACHED_IN_MIGRATION();
-  delegate = nullptr;
+  NOTREACHED();
 #endif
 
+#if BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_WIN) || \
+    BUILDFLAG(IS_MAC)
   if (ui_factory_) {
     delegate->set_ui_delegate(ui_factory_->CreateDelegate());
   }
 
   return delegate;
+#endif
 }
 
 BrowserContext* NetworkingPrivateDelegateFactory::GetBrowserContextToUse(

extensions/browser/api/power/power_api.cc

@@ -28,9 +28,7 @@ device::mojom::WakeLockType LevelToWakeLockType(api::power::Level level) {
     case api::power::Level::kNone:
       return device::mojom::WakeLockType::kPreventDisplaySleep;
   }
-  NOTREACHED_IN_MIGRATION()
-      << "Unhandled power level: " << api::power::ToString(level);
-  return device::mojom::WakeLockType::kPreventDisplaySleep;
+  NOTREACHED() << "Unhandled power level: " << api::power::ToString(level);
 }
 
 base::LazyInstance<BrowserContextKeyedAPIFactory<PowerAPI>>::DestructorAtExit

extensions/browser/api/power/power_api_unittest.cc

@@ -92,8 +92,7 @@ class FakeWakeLockManager {
           requests_.push_back(UNBLOCK_APP_SUSPENSION);
           break;
         case device::mojom::WakeLockType::kPreventDisplaySleepAllowDimming:
-          NOTREACHED_IN_MIGRATION() << "Unexpected wake lock type " << type;
-          break;
+          NOTREACHED() << "Unexpected wake lock type " << type;
       }
 
       type_ = type;
@@ -110,8 +109,7 @@ class FakeWakeLockManager {
           requests_.push_back(BLOCK_DISPLAY_SLEEP);
           break;
         case device::mojom::WakeLockType::kPreventDisplaySleepAllowDimming:
-          NOTREACHED_IN_MIGRATION() << "Unexpected wake lock type " << type;
-          break;
+          NOTREACHED() << "Unexpected wake lock type " << type;
       }
 
       type_ = type;
@@ -130,8 +128,7 @@ class FakeWakeLockManager {
         requests_.push_back(UNBLOCK_DISPLAY_SLEEP);
         break;
       case device::mojom::WakeLockType::kPreventDisplaySleepAllowDimming:
-        NOTREACHED_IN_MIGRATION() << "Unexpected wake lock type " << type_;
-        break;
+        NOTREACHED() << "Unexpected wake lock type " << type_;
     }
     is_active_ = false;
   }

extensions/browser/api/runtime/runtime_api.cc

@@ -92,7 +92,6 @@ constexpr char kErrorOnlyKioskModeAllowed[] =
     "API available only for ChromeOS kiosk mode.";
 constexpr char kErrorOnlyFirstExtensionAllowed[] =
     "Not the first extension to call this API.";
-constexpr char kErrorInvalidStatus[] = "Invalid restart request status.";
 constexpr char kErrorRequestedTooSoon[] =
     "Restart was requested too soon. It was throttled instead.";
 
@@ -768,8 +767,7 @@ ExtensionFunction::ResponseAction RuntimeRestartAfterDelayFunction::Run() {
       return RespondNow(NoArguments());
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return RespondNow(Error(kErrorInvalidStatus));
+  NOTREACHED();
 }
 
 ExtensionFunction::ResponseAction RuntimeGetPlatformInfoFunction::Run() {

extensions/browser/api/serial/serial_apitest.cc

@@ -140,10 +140,10 @@ class FakeSerialPort : public device::mojom::SerialPort {
       return;
     }
 
-    NOTREACHED_IN_MIGRATION();
+    NOTREACHED();
   }
 
-  void Drain(DrainCallback callback) override { NOTREACHED_IN_MIGRATION(); }
+  void Drain(DrainCallback callback) override { NOTREACHED(); }
 
   void GetControlSignals(GetControlSignalsCallback callback) override {
     auto signals = device::mojom::SerialPortControlSignals::New();
@@ -214,7 +214,7 @@ class FakeSerialPort : public device::mojom::SerialPort {
       return;
     }
     // The code should not reach other cases.
-    NOTREACHED_IN_MIGRATION();
+    NOTREACHED();
   }
 
   void DoRead(MojoResult result, const mojo::HandleSignalsState& state) {

extensions/browser/api/socket/app_firewall_hole_manager.cc

@@ -138,7 +138,7 @@ void AppFirewallHoleManager::Close(AppFirewallHole* hole) {
       return;
     }
   }
-  NOTREACHED_IN_MIGRATION();
+  NOTREACHED();
 }
 
 void AppFirewallHoleManager::OnAppWindowRemoved(AppWindow* app_window) {

extensions/browser/api/socket/socket_api.cc

@@ -140,10 +140,7 @@ void SocketApiFunction::OpenFirewallHole(const std::string& address,
   if (!net::HostStringIsLocalhost(address)) {
     net::IPEndPoint local_address;
     if (!socket->GetLocalAddress(&local_address)) {
-      NOTREACHED_IN_MIGRATION()
-          << "Cannot get address of recently bound socket.";
-      Respond(ErrorWithCode(-1, kFirewallFailure));
-      return;
+      NOTREACHED() << "Cannot get address of recently bound socket.";
     }
 
     AppFirewallHoleManager* manager =
@@ -318,8 +315,7 @@ ExtensionFunction::ResponseAction SocketCreateFunction::Work() {
       break;
     }
     case extensions::api::socket::SocketType::kNone:
-      NOTREACHED_IN_MIGRATION();
-      return RespondNow(NoArguments());
+      NOTREACHED();
   }
 
   DCHECK(socket);
@@ -374,9 +370,7 @@ ExtensionFunction::ResponseAction SocketConnectFunction::Work() {
       operation_type = SocketPermissionRequest::UDP_SEND_TO;
       break;
     default:
-      NOTREACHED_IN_MIGRATION() << "Unknown socket type.";
-      operation_type = SocketPermissionRequest::NONE;
-      break;
+      NOTREACHED() << "Unknown socket type.";
   }
 
   SocketPermission::CheckParam param(operation_type, hostname_, port_);

extensions/browser/api/sockets_udp/test_udp_echo_server.cc

@@ -70,7 +70,7 @@ class TestUdpEchoServer::Core {
         udp_listener_receiver_.BindNewPipeAndPassRemote());
 
     server_socket_.set_disconnect_handler(
-        base::BindLambdaForTesting([]() { NOTREACHED_IN_MIGRATION(); }));
+        base::BindLambdaForTesting([]() { NOTREACHED(); }));
 
     net::IPEndPoint server_addr(net::IPAddress::IPv4Localhost(), 0);
     auto server_helper =

extensions/browser/api/storage/settings_namespace.cc

@@ -27,8 +27,7 @@ std::string ToString(Namespace settings_namespace) {
     case INVALID:
       break;
   }
-  NOTREACHED_IN_MIGRATION();
-  return std::string();
+  NOTREACHED();
 }
 
 }  // namespace settings_namespace

extensions/browser/api/storage/settings_test_util.cc

@@ -96,7 +96,7 @@ scoped_refptr<const Extension> AddExtensionWithIdAndPermissions(
     }
 
     default:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
 
   std::string error;

extensions/browser/api/storage/storage_api_unittest.cc

@@ -240,48 +240,32 @@ TEST_F(StorageApiUnittest, GetBytesInUseIntOverflow) {
 
     size_t GetBytesInUse() override { return bytes_in_use_; }
 
-    ReadResult Get(const std::string& key) override {
-      NOTREACHED_IN_MIGRATION();
-      return ReadResult(Status());
-    }
+    ReadResult Get(const std::string& key) override { NOTREACHED(); }
 
     ReadResult Get(const std::vector<std::string>& keys) override {
-      NOTREACHED_IN_MIGRATION();
-      return ReadResult(Status());
+      NOTREACHED();
     }
 
-    ReadResult Get() override {
-      NOTREACHED_IN_MIGRATION();
-      return ReadResult(Status());
-    }
+    ReadResult Get() override { NOTREACHED(); }
 
     WriteResult Set(WriteOptions options,
                     const std::string& key,
                     const base::Value& value) override {
-      NOTREACHED_IN_MIGRATION();
-      return WriteResult(Status());
+      NOTREACHED();
     }
 
     WriteResult Set(WriteOptions options,
                     const base::Value::Dict& values) override {
-      NOTREACHED_IN_MIGRATION();
-      return WriteResult(Status());
+      NOTREACHED();
     }
 
-    WriteResult Remove(const std::string& key) override {
-      NOTREACHED_IN_MIGRATION();
-      return WriteResult(Status());
-    }
+    WriteResult Remove(const std::string& key) override { NOTREACHED(); }
 
     WriteResult Remove(const std::vector<std::string>& keys) override {
-      NOTREACHED_IN_MIGRATION();
-      return WriteResult(Status());
+      NOTREACHED();
     }
 
-    WriteResult Clear() override {
-      NOTREACHED_IN_MIGRATION();
-      return WriteResult(Status());
-    }
+    WriteResult Clear() override { NOTREACHED(); }
 
    private:
     size_t bytes_in_use_ = 0;

extensions/browser/api/storage/storage_area_namespace.cc

@@ -26,8 +26,7 @@ const char* StorageAreaToString(StorageAreaNamespace storage_area) {
     case StorageAreaNamespace::kSession:
       return kSessionString;
     case StorageAreaNamespace::kInvalid:
-      NOTREACHED_IN_MIGRATION();
-      return "";
+      NOTREACHED();
   }
 }
 
@@ -43,8 +42,7 @@ settings_namespace::Namespace StorageAreaToSettingsNamespace(
     case StorageAreaNamespace::kSession:
       return settings_namespace::INVALID;
     case StorageAreaNamespace::kInvalid:
-      NOTREACHED_IN_MIGRATION();
-      return settings_namespace::INVALID;
+      NOTREACHED();
   }
 }
 

extensions/browser/api/storage/storage_frontend.cc

@@ -56,8 +56,7 @@ events::HistogramValue StorageAreaToEventHistogram(
     case StorageAreaNamespace::kSession:
       return events::STORAGE_SESSION_ON_CHANGE;
     case StorageAreaNamespace::kInvalid:
-      NOTREACHED_IN_MIGRATION();
-      return events::UNKNOWN;
+      NOTREACHED();
   }
 }
 

extensions/browser/api/storage/value_store_util.cc

@@ -36,7 +36,7 @@ base::FilePath GetValueStoreDir(
       dir = base::FilePath(kManagedSettingsDirectoryName);
       break;
     case settings_namespace::INVALID:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
   return dir.AppendASCII(id);
 }

extensions/browser/api/system_display/display_info_provider.cc

@@ -106,12 +106,12 @@ void DisplayInfoProvider::SetDisplayProperties(
     const std::string& display_id,
     const api::system_display::DisplayProperties& properties,
     ErrorCallback callback) {
-  NOTREACHED_IN_MIGRATION() << "SetDisplayProperties not implemented";
+  NOTREACHED() << "SetDisplayProperties not implemented";
 }
 
 void DisplayInfoProvider::SetDisplayLayout(const DisplayLayoutList& layouts,
                                            ErrorCallback callback) {
-  NOTREACHED_IN_MIGRATION() << "SetDisplayLayout not implemented";
+  NOTREACHED() << "SetDisplayLayout not implemented";
 }
 
 void DisplayInfoProvider::EnableUnifiedDesktop(bool enable) {}
@@ -148,9 +148,7 @@ void DisplayInfoProvider::GetAllDisplaysInfo(
 
 void DisplayInfoProvider::GetDisplayLayout(
     base::OnceCallback<void(DisplayLayoutList result)> callback) {
-  NOTREACHED_IN_MIGRATION();  // Implemented on Chrome OS only in override.
-  base::SingleThreadTaskRunner::GetCurrentDefault()->PostTask(
-      FROM_HERE, base::BindOnce(std::move(callback), DisplayLayoutList()));
+  NOTREACHED();  // Implemented on Chrome OS only in override.
 }
 
 void DisplayInfoProvider::StartObserving() {
@@ -181,32 +179,27 @@ bool DisplayInfoProvider::OverscanCalibrationComplete(const std::string& id) {
 
 void DisplayInfoProvider::ShowNativeTouchCalibration(const std::string& id,
                                                      ErrorCallback callback) {
-  NOTREACHED_IN_MIGRATION();  // Implemented on Chrome OS only in override.
+  NOTREACHED();  // Implemented on Chrome OS only in override.
 }
 
 bool DisplayInfoProvider::StartCustomTouchCalibration(const std::string& id) {
-  NOTREACHED_IN_MIGRATION();  // Implemented on Chrome OS only in override.
-  return false;
+  NOTREACHED();  // Implemented on Chrome OS only in override.
 }
 
 bool DisplayInfoProvider::CompleteCustomTouchCalibration(
     const api::system_display::TouchCalibrationPairQuad& pairs,
     const api::system_display::Bounds& bounds) {
-  NOTREACHED_IN_MIGRATION();  // Implemented on Chrome OS only in override.
-  return false;
+  NOTREACHED();  // Implemented on Chrome OS only in override.
 }
 
 bool DisplayInfoProvider::ClearTouchCalibration(const std::string& id) {
-  NOTREACHED_IN_MIGRATION();  // Implemented on Chrome OS only in override.
-  return false;
+  NOTREACHED();  // Implemented on Chrome OS only in override.
 }
 
 void DisplayInfoProvider::SetMirrorMode(
     const api::system_display::MirrorModeInfo& info,
     ErrorCallback callback) {
-  NOTREACHED_IN_MIGRATION();  // Implemented on Chrome OS only in override.
-  base::SingleThreadTaskRunner::GetCurrentDefault()->PostTask(
-      FROM_HERE, base::BindOnce(std::move(callback), "Not supported"));
+  NOTREACHED();  // Implemented on Chrome OS only in override.
 }
 
 void DisplayInfoProvider::DispatchOnDisplayChangedEvent() {

extensions/browser/api/system_info/system_info_api.cc

@@ -250,7 +250,7 @@ void HandleListenerAddedOrRemoved(content::BrowserContext* context,
     return;
   }
 
-  NOTREACHED_IN_MIGRATION() << "Unknown event name: " << event_name;
+  NOTREACHED() << "Unknown event name: " << event_name;
 }
 
 }  // namespace

extensions/browser/api/usb/usb_api.cc

@@ -141,8 +141,7 @@ bool ConvertDirectionFromApi(const Direction& input,
       *output = UsbTransferDirection::OUTBOUND;
       return true;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return false;
+      NOTREACHED();
   }
 }
 
@@ -162,8 +161,7 @@ bool ConvertRequestTypeFromApi(const RequestType& input,
       *output = UsbControlTransferType::RESERVED;
       return true;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return false;
+      NOTREACHED();
   }
 }
 
@@ -183,8 +181,7 @@ bool ConvertRecipientFromApi(const Recipient& input,
       *output = UsbControlTransferRecipient::OTHER;
       return true;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return false;
+      NOTREACHED();
   }
 }
 
@@ -244,8 +241,7 @@ TransferType ConvertTransferTypeToApi(const UsbTransferType& input) {
     case UsbTransferType::BULK:
       return usb::TransferType::kBulk;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return usb::TransferType::kNone;
+      NOTREACHED();
   }
 }
 
@@ -256,8 +252,7 @@ Direction ConvertDirectionToApi(const UsbTransferDirection& input) {
     case UsbTransferDirection::OUTBOUND:
       return usb::Direction::kOut;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return usb::Direction::kNone;
+      NOTREACHED();
   }
 }
 
@@ -273,8 +268,7 @@ SynchronizationType ConvertSynchronizationTypeToApi(
     case UsbSynchronizationType::SYNCHRONOUS:
       return usb::SynchronizationType::kSynchronous;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return usb::SynchronizationType::kNone;
+      NOTREACHED();
   }
 }
 
@@ -293,8 +287,7 @@ usb::UsageType ConvertUsageTypeToApi(const UsbUsageType& input) {
     case UsbUsageType::RESERVED:
       return usb::UsageType::kNone;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return usb::UsageType::kNone;
+      NOTREACHED();
   }
 }
 

extensions/browser/api/web_contents_capture_client.cc

@@ -94,7 +94,7 @@ std::optional<std::string> WebContentsCaptureClient::EncodeBitmap(
       mime_type = kMimeTypePng;
       break;
     default:
-      NOTREACHED_IN_MIGRATION() << "Invalid image format.";
+      NOTREACHED() << "Invalid image format.";
   }
 
   if (!data) {

extensions/browser/api/web_request/extension_web_request_event_router.cc

@@ -143,9 +143,7 @@ events::HistogramValue GetEventHistogramValue(const std::string& event_name) {
 
   // There is no histogram value for this event name. It should be added to
   // either the mapping here, or in guest_view_events.
-  NOTREACHED_IN_MIGRATION()
-      << "Event " << event_name << " must have a histogram value";
-  return events::UNKNOWN;
+  NOTREACHED() << "Event " << event_name << " must have a histogram value";
 }
 
 const char* GetRequestStageAsString(WebRequestEventRouter::EventTypes type) {
@@ -171,8 +169,7 @@ const char* GetRequestStageAsString(WebRequestEventRouter::EventTypes type) {
     case WebRequestEventRouter::kOnCompleted:
       return keys::kOnCompleted;
   }
-  NOTREACHED_IN_MIGRATION();
-  return "Not reached";
+  NOTREACHED();
 }
 
 void LogRequestAction(RequestAction action) {
@@ -607,8 +604,7 @@ helpers::EventResponseDelta CalculateDelta(
           response->extension_id, response->extension_install_time,
           response->cancel, response->auth_credentials);
     default:
-      NOTREACHED_IN_MIGRATION();
-      return helpers::EventResponseDelta("", base::Time());
+      NOTREACHED();
   }
 }
 
@@ -2438,7 +2434,7 @@ int WebRequestEventRouter::ExecuteDeltas(
         blocked_request.response_deltas, blocked_request.auth_credentials,
         &ignored_actions);
   } else {
-    NOTREACHED_IN_MIGRATION();
+    NOTREACHED();
   }
 
   SendMessages(browser_context, blocked_request);

extensions/browser/api/web_request/form_data_parser.cc

@@ -351,9 +351,7 @@ std::unique_ptr<FormDataParser> FormDataParser::CreateFromContentTypeHeader(
     case ERROR_CHOICE:
       return nullptr;
   }
-  NOTREACHED_IN_MIGRATION();  // Some compilers do not believe this is
-                              // unreachable.
-  return nullptr;
+  NOTREACHED();  // Some compilers do not believe this is unreachable.
 }
 
 FormDataParser::FormDataParser() = default;

extensions/browser/api/web_request/web_request_api_helpers.cc

@@ -380,8 +380,7 @@ struct DNRHeaderAction {
       case dnr_api::HeaderOperation::kRemove:
         return true;
       case dnr_api::HeaderOperation::kNone:
-        NOTREACHED_IN_MIGRATION();
-        return true;
+        NOTREACHED();
     }
   }
 
@@ -463,7 +462,7 @@ bool ModifyRequestHeadersForAction(
         break;
       }
       case dnr_api::HeaderOperation::kNone:
-        NOTREACHED_IN_MIGRATION();
+        NOTREACHED();
     }
 
     request_headers_modified |= header_modified;
@@ -561,7 +560,7 @@ bool ModifyResponseHeadersForAction(
         break;
       }
       case dnr_api::HeaderOperation::kNone:
-        NOTREACHED_IN_MIGRATION();
+        NOTREACHED();
     }
 
     response_headers_modified |= header_modified;

extensions/browser/api/web_request/web_request_permissions.cc

@@ -180,8 +180,7 @@ PermissionsData::PageAccess CanExtensionAccessURLInternal(
                  : PermissionsData::PageAccess::kDenied;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return PermissionsData::PageAccess::kDenied;
+  NOTREACHED();
 }
 
 // Returns true if |request|.url is of the form clients[0-9]*.google.com.

extensions/browser/api/web_request/web_request_proxying_url_loader_factory.cc

@@ -904,7 +904,7 @@ void WebRequestProxyingURLLoaderFactory::InProgressRequest::
         pending_follow_redirect_params_->modified_headers.SetHeader(
             set_header, *header_value);
       } else {
-        NOTREACHED_IN_MIGRATION();
+        NOTREACHED();
       }
     }
 
@@ -1030,8 +1030,7 @@ void WebRequestProxyingURLLoaderFactory::InProgressRequest::
       state_ = State::kRejectedByOnAuthRequired;
       break;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return;
+      NOTREACHED();
   }
 
   auth_credentials_ = std::nullopt;

extensions/browser/api/web_request/web_request_proxying_websocket.cc

@@ -486,8 +486,7 @@ void WebRequestProxyingWebSocket::OnAuthRequiredComplete(
       break;
     case WebRequestEventRouter::AuthRequiredResponse::
         AUTH_REQUIRED_RESPONSE_IO_PENDING:
-      NOTREACHED_IN_MIGRATION();
-      break;
+      NOTREACHED();
   }
 }
 

extensions/browser/api/web_request/web_request_resource_type.cc

@@ -116,8 +116,7 @@ WebRequestResourceType ToWebRequestResourceType(
     case network::mojom::RequestDestination::kSpeculationRules:
       return WebRequestResourceType::OTHER;
   }
-  NOTREACHED_IN_MIGRATION();
-  return WebRequestResourceType::OTHER;
+  NOTREACHED();
 }
 
 const char* WebRequestResourceTypeToString(WebRequestResourceType type) {

extensions/browser/blocklist_extension_prefs.cc

@@ -79,9 +79,7 @@ BitMapBlocklistState BlocklistStateToBitMapBlocklistState(
     case BLOCKLISTED_POTENTIALLY_UNWANTED:
       return BitMapBlocklistState::BLOCKLISTED_POTENTIALLY_UNWANTED;
     case BLOCKLISTED_UNKNOWN:
-      NOTREACHED_IN_MIGRATION()
-          << "The unknown state should not be added into prefs.";
-      return BitMapBlocklistState::NOT_BLOCKLISTED;
+      NOTREACHED() << "The unknown state should not be added into prefs.";
   }
 }
 

extensions/browser/browser_frame_context_data.cc

@@ -74,13 +74,11 @@ url::Origin BrowserFrameContextData::GetOrigin() const {
 // BrowserFrameContextData::CanAccess is unable to replicate all of the
 // WebSecurityOrigin::CanAccess checks, so these methods should not be called.
 bool BrowserFrameContextData::CanAccess(const url::Origin& target) const {
-  NOTREACHED_IN_MIGRATION();
-  return true;
+  NOTREACHED();
 }
 
 bool BrowserFrameContextData::CanAccess(const FrameContextData& target) const {
-  NOTREACHED_IN_MIGRATION();
-  return true;
+  NOTREACHED();
 }
 
 uintptr_t BrowserFrameContextData::GetId() const {

extensions/browser/embedder_user_script_loader.cc

@@ -151,8 +151,7 @@ void EmbedderUserScriptLoader::CreateEmbedderURLFetchers(
         NOTREACHED();
 #endif
       case extensions::mojom::HostID::HostType::kExtensions:
-        NOTREACHED_IN_MIGRATION();
-        break;
+        NOTREACHED();
     }
     fetchers_.push_back(std::move(fetcher));
   }

extensions/browser/extension_function.cc

@@ -611,7 +611,7 @@ bool ExtensionFunction::ShouldKeepWorkerAliveIndefinitely() {
 void ExtensionFunction::OnResponseAck() {
   // Derived classes must override this if they require and implement an
   // ACK from the renderer.
-  NOTREACHED_IN_MIGRATION();
+  NOTREACHED();
 }
 
 ExtensionFunction::ResponseValue ExtensionFunction::NoArguments() {

extensions/browser/extension_function_dispatcher.cc

@@ -111,9 +111,7 @@ const char* ToString(bad_message::BadMessageReason bad_message_code) {
     case bad_message::BadMessageReason::EFD_INVALID_EXTENSION_ID_FOR_PROCESS:
       return "LocalFrameHost::Request: renderer never hosted such extension";
     default:
-      NOTREACHED_IN_MIGRATION();
-      return "LocalFrameHost::Request encountered unrecognized validation "
-             "error.";
+      NOTREACHED();
   }
 }
 

extensions/browser/extension_icon_placeholder.cc

@@ -36,8 +36,7 @@ ui::ResourceBundle::FontStyle GetFontStyleForIconSize(
     case extension_misc::EXTENSION_ICON_GIGANTOR:
       return ui::ResourceBundle::LargeFont;
   }
-  NOTREACHED_IN_MIGRATION();
-  return ui::ResourceBundle::MediumFont;
+  NOTREACHED();
 }
 
 // Returns the background image to use for the given icon |size|.

extensions/browser/extension_pref_value_map.cc

@@ -72,11 +72,10 @@ bool ExtensionPrefValueMap::CanExtensionControlPref(
     bool incognito) const {
   auto ext = entries_.find(extension_id);
   if (ext == entries_.end()) {
-    NOTREACHED_IN_MIGRATION()
-        << "Extension " << extension_id
-        << " is not registered but accesses pref " << pref_key
-        << " (incognito: " << incognito << ")." << " http://crbug.com/454513";
-    return false;
+    NOTREACHED() << "Extension " << extension_id
+                 << " is not registered but accesses pref " << pref_key
+                 << " (incognito: " << incognito << ")."
+                 << " http://crbug.com/454513";
   }
 
   if (incognito && !ext->second->incognito_enabled)
@@ -191,8 +190,7 @@ PrefValueMap* ExtensionPrefValueMap::GetExtensionPrefValueMap(
     case ChromeSettingScope::kNone:
       break;
   }
-  NOTREACHED_IN_MIGRATION();
-  return nullptr;
+  NOTREACHED();
 }
 
 const PrefValueMap* ExtensionPrefValueMap::GetExtensionPrefValueMap(
@@ -212,8 +210,7 @@ const PrefValueMap* ExtensionPrefValueMap::GetExtensionPrefValueMap(
     case ChromeSettingScope::kNone:
       break;
   }
-  NOTREACHED_IN_MIGRATION();
-  return nullptr;
+  NOTREACHED();
 }
 
 void ExtensionPrefValueMap::GetExtensionControlledKeys(

extensions/browser/extension_prefs.cc

@@ -467,9 +467,7 @@ void ExtensionPrefs::MakePathsRelative() {
   for (const std::string& key : absolute_keys) {
     std::unique_ptr<prefs::DictionaryValueUpdate> extension_dict;
     if (!update_dict->GetDictionaryWithoutPathExpansion(key, &extension_dict)) {
-      NOTREACHED_IN_MIGRATION()
-          << "Control should never reach here for extension " << key;
-      continue;
+      NOTREACHED() << "Control should never reach here for extension " << key;
     }
     std::string path_string;
     extension_dict->GetString(kPrefPath, &path_string);
@@ -554,8 +552,7 @@ void ExtensionPrefs::UpdateExtensionPref(
     std::string_view key,
     std::optional<base::Value> data_value) {
   if (!crx_file::id_util::IdIsValid(extension_id)) {
-    NOTREACHED_IN_MIGRATION() << "Invalid extension_id " << extension_id;
-    return;
+    NOTREACHED() << "Invalid extension_id " << extension_id;
   }
   ScopedExtensionPrefUpdate update(prefs_, extension_id);
   if (data_value) {
@@ -1469,8 +1466,7 @@ std::optional<ExtensionInfo> ExtensionPrefs::GetInstalledInfoHelper(
       location != ManifestLocation::kComponent &&
       !Manifest::IsUnpackedLocation(location) &&
       !Manifest::IsExternalLocation(location)) {
-    NOTREACHED_IN_MIGRATION();
-    return std::nullopt;
+    NOTREACHED();
   }
 
   const base::Value* manifest = extension.Find(kPrefManifest);
@@ -2152,8 +2148,7 @@ bool ExtensionPrefs::GetUserExtensionPrefIntoContainer(
       *id_container_out, id_container_out->end());
   for (const auto& entry : user_pref_value->GetList()) {
     if (!entry.is_string()) {
-      NOTREACHED_IN_MIGRATION();
-      continue;
+      NOTREACHED();
     }
     insert_iterator = entry.GetString();
   }

extensions/browser/extension_user_script_loader.cc

@@ -318,7 +318,7 @@ void LoadUserScripts(
         dynamic_script_length += script_files_length;
         break;
       case UserScript::Source::kWebUIScript:
-        NOTREACHED_IN_MIGRATION();
+        NOTREACHED();
     }
   }
 

extensions/browser/guest_view/app_view/app_view_guest.cc

@@ -262,7 +262,7 @@ void AppViewGuest::DidInitialize(const base::Value::Dict& create_params) {
 void AppViewGuest::MaybeRecreateGuestContents(
     content::RenderFrameHost* outer_contents_frame) {
   // This situation is not possible for AppView.
-  NOTREACHED_IN_MIGRATION();
+  NOTREACHED();
 }
 
 const char* AppViewGuest::GetAPINamespace() const {

extensions/browser/guest_view/extension_options/extension_options_guest.cc

@@ -115,7 +115,7 @@ void ExtensionOptionsGuest::DidInitialize(
 void ExtensionOptionsGuest::MaybeRecreateGuestContents(
     content::RenderFrameHost* outer_contents_frame) {
   // This situation is not possible for ExtensionOptions.
-  NOTREACHED_IN_MIGRATION();
+  NOTREACHED();
 }
 
 void ExtensionOptionsGuest::GuestViewDidStopLoading() {
@@ -213,8 +213,7 @@ bool ExtensionOptionsGuest::HandleContextMenu(
 
 bool ExtensionOptionsGuest::ShouldResumeRequestsForCreatedWindow() {
   // Not reached due to the use of `CreateCustomWebContents`.
-  NOTREACHED_IN_MIGRATION();
-  return true;
+  NOTREACHED();
 }
 
 bool ExtensionOptionsGuest::IsWebContentsCreationOverridden(

extensions/browser/guest_view/mime_handler_view/mime_handler_view_guest.cc

@@ -227,7 +227,7 @@ void MimeHandlerViewGuest::DidInitialize(
 void MimeHandlerViewGuest::MaybeRecreateGuestContents(
     content::RenderFrameHost* outer_contents_frame) {
   // This situation is not possible for MimeHandlerView.
-  NOTREACHED_IN_MIGRATION();
+  NOTREACHED();
 }
 
 void MimeHandlerViewGuest::EmbedderFullscreenToggled(bool entered_fullscreen) {
@@ -381,8 +381,7 @@ bool MimeHandlerViewGuest::IsFullscreenForTabOrPending(
 
 bool MimeHandlerViewGuest::ShouldResumeRequestsForCreatedWindow() {
   // Not reached due to the use of `CreateCustomWebContents`.
-  NOTREACHED_IN_MIGRATION();
-  return true;
+  NOTREACHED();
 }
 
 bool MimeHandlerViewGuest::IsWebContentsCreationOverridden(

extensions/browser/guest_view/web_view/javascript_dialog_helper.cc

@@ -29,8 +29,7 @@ std::string JavaScriptDialogTypeToString(
     case content::JAVASCRIPT_DIALOG_TYPE_PROMPT:
       return "prompt";
     default:
-      NOTREACHED_IN_MIGRATION() << "Unknown JavaScript Message Type.";
-      return "unknown";
+      NOTREACHED() << "Unknown JavaScript Message Type.";
   }
 }
 

extensions/browser/guest_view/web_view/web_view_guest.cc

@@ -157,8 +157,7 @@ std::string WindowOpenDispositionToString(
     case WindowOpenDisposition::NEW_POPUP:
       return "new_popup";
     default:
-      NOTREACHED_IN_MIGRATION() << "Unknown Window Open Disposition";
-      return "ignore";
+      NOTREACHED() << "Unknown Window Open Disposition";
   }
 }
 
@@ -188,8 +187,7 @@ static std::string TerminationStatusToString(base::TerminationStatus status) {
     case base::TERMINATION_STATUS_MAX_ENUM:
       break;
   }
-  NOTREACHED_IN_MIGRATION() << "Unknown Termination Status.";
-  return "unknown";
+  NOTREACHED() << "Unknown Termination Status.";
 }
 
 std::string GetStoragePartitionIdFromPartitionConfig(
@@ -1049,8 +1047,7 @@ void WebViewGuest::ReportFrameNameChange(const std::string& name) {
 void WebViewGuest::PushWebViewStateToIOThread(
     content::RenderFrameHost* guest_host) {
   if (!guest_host->GetSiteInstance()->IsGuest()) {
-    NOTREACHED_IN_MIGRATION();
-    return;
+    NOTREACHED();
   }
   auto storage_partition_config =
       guest_host->GetSiteInstance()->GetStoragePartitionConfig();

extensions/browser/guest_view/web_view/web_view_permission_helper.cc

@@ -55,8 +55,7 @@ static std::string PermissionTypeToString(WebViewPermissionType type) {
     case WEB_VIEW_PERMISSION_TYPE_POINTER_LOCK:
       return webview::kPermissionTypePointerLock;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return std::string();
+      NOTREACHED();
   }
 }
 

extensions/browser/image_loader.cc

@@ -51,8 +51,7 @@ bool ShouldResizeImageRepresentation(
     case ImageLoader::ImageRepresentation::NEVER_RESIZE:
       return false;
     default:
-      NOTREACHED_IN_MIGRATION();
-      return false;
+      NOTREACHED();
   }
 }
 

extensions/browser/mock_extension_system.cc

@@ -86,7 +86,7 @@ void MockExtensionSystem::InstallUpdate(
     const base::FilePath& temp_dir,
     bool install_immediately,
     InstallUpdateCallback install_update_callback) {
-  NOTREACHED_IN_MIGRATION();
+  NOTREACHED();
 }
 
 void MockExtensionSystem::PerformActionBasedOnOmahaAttributes(
@@ -96,8 +96,7 @@ void MockExtensionSystem::PerformActionBasedOnOmahaAttributes(
 bool MockExtensionSystem::FinishDelayedInstallationIfReady(
     const ExtensionId& extension_id,
     bool install_immediately) {
-  NOTREACHED_IN_MIGRATION();
-  return false;
+  NOTREACHED();
 }
 
 }  // namespace extensions

extensions/browser/pref_names.cc

@@ -29,8 +29,7 @@ bool ScopeToPrefName(ChromeSettingScope scope, std::string* result) {
     case ChromeSettingScope::kNone:
       break;
   }
-  NOTREACHED_IN_MIGRATION();
-  return false;
+  NOTREACHED();
 }
 
 const char kPrefPreferences[] = "preferences";

extensions/browser/process_manager.cc

@@ -166,8 +166,7 @@ struct ProcessManager::ExtensionRenderFrameData {
       case extensions::mojom::ViewType::kExtensionSidePanel:
         return false;
     }
-    NOTREACHED_IN_MIGRATION();
-    return false;
+    NOTREACHED();
   }
 };
 

extensions/browser/renderer_startup_helper.cc

@@ -294,13 +294,9 @@ void RendererStartupHelper::ActivateExtensionInProcess(
   // The extension should have been loaded already. Dump without crashing to
   // debug crbug.com/528026.
   if (!base::Contains(extension_process_map_, extension.id())) {
-#if DCHECK_IS_ON()
-    NOTREACHED_IN_MIGRATION()
+    DUMP_WILL_BE_NOTREACHED()
         << "Extension " << extension.id() << " activated before loading";
-#else
-    base::debug::DumpWithoutCrashing();
     return;
-#endif
   }
 
   if (!util::IsExtensionVisibleToContext(extension,
@@ -576,9 +572,7 @@ void RendererStartupHelper::GetMessageBundle(
     const Extension* imported_extension =
         extension_set.GetByID(import.extension_id);
     if (!imported_extension) {
-      NOTREACHED_IN_MIGRATION()
-          << "Missing shared module " << import.extension_id;
-      continue;
+      NOTREACHED() << "Missing shared module " << import.extension_id;
     }
     paths_to_load.push_back(imported_extension->path());
   }

extensions/browser/sandboxed_unpacker.cc

@@ -669,8 +669,7 @@ void SandboxedUnpacker::OnImageSanitizationDone(
                                          u"ERROR_SAVING_THEME_IMAGE");
       break;
     default:
-      NOTREACHED_IN_MIGRATION();
-      break;
+      NOTREACHED();
   }
 
   ReportFailure(failure_reason, error);
@@ -735,8 +734,7 @@ void SandboxedUnpacker::MessageCatalogsSanitized(
                                          u"ERROR_SAVING_CATALOG");
       break;
     default:
-      NOTREACHED_IN_MIGRATION();
-      break;
+      NOTREACHED();
   }
 
   ReportFailure(failure_reason, error);
@@ -919,8 +917,7 @@ std::u16string SandboxedUnpacker::FailureReasonToString16(
     case SandboxedUnpackerFailureReason::DEPRECATED_ERROR_PARSING_DNR_RULESET:
     case SandboxedUnpackerFailureReason::NUM_FAILURE_REASONS:
     default:
-      NOTREACHED_IN_MIGRATION();
-      return std::u16string();
+      NOTREACHED();
   }
 }
 

extensions/browser/test_extensions_browser_client.cc

@@ -168,7 +168,7 @@ void TestExtensionsBrowserClient::LoadResourceFromResourceBundle(
     scoped_refptr<net::HttpResponseHeaders> headers,
     mojo::PendingRemote<network::mojom::URLLoaderClient> client) {
   // Should not be called because GetBundleResourcePath() returned empty path.
-  NOTREACHED_IN_MIGRATION() << "Resource is not from a bundle.";
+  NOTREACHED() << "Resource is not from a bundle.";
 }
 
 bool TestExtensionsBrowserClient::AllowCrossRendererResourceLoad(

extensions/browser/updater/extension_downloader.cc

@@ -1466,10 +1466,8 @@ bool ExtensionDownloader::IterateFetchCredentialsAfterFailure(
       }
       return false;
     default:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
-  NOTREACHED_IN_MIGRATION();
-  return false;
 }
 
 void ExtensionDownloader::OnAccessTokenFetchComplete(

extensions/browser/updater/extension_installer.cc

@@ -66,8 +66,7 @@ std::optional<base::FilePath> ExtensionInstaller::GetInstalledFile(
 }
 
 bool ExtensionInstaller::Uninstall() {
-  NOTREACHED_IN_MIGRATION();
-  return false;
+  NOTREACHED();
 }
 
 ExtensionInstaller::~ExtensionInstaller() = default;

extensions/browser/updater/manifest_fetch_data.cc

@@ -91,8 +91,7 @@ std::string ManifestFetchData::GetSimpleLocationString(ManifestLocation loc) {
       result = kPolicyLocation;
       break;
     case ManifestLocation::kInvalidLocation:
-      NOTREACHED_IN_MIGRATION();
-      break;
+      NOTREACHED();
   }
 
   return result;
@@ -147,8 +146,7 @@ bool ManifestFetchData::AddExtension(const std::string& id,
   DCHECK(!is_all_external_policy_download_ ||
          extension_location == ManifestLocation::kExternalPolicyDownload);
   if (base::Contains(extensions_data_, id)) {
-    NOTREACHED_IN_MIGRATION() << "Duplicate extension id " << id;
-    return false;
+    NOTREACHED() << "Duplicate extension id " << id;
   }
 
   if (fetch_priority_ != DownloadFetchPriority::kForeground) {
@@ -280,7 +278,7 @@ bool ManifestFetchData::DidPing(const ExtensionId& extension_id,
   else if (type == ACTIVE)
     value = i->second.active_days;
   else
-    NOTREACHED_IN_MIGRATION();
+    NOTREACHED();
   return value == kNeverPinged || value > 0;
 }
 

extensions/browser/updater/update_service_unittest.cc

@@ -108,7 +108,7 @@ class FakeUpdateClient : public update_client::UpdateClient {
                       CrxStateChangeCallback crx_state_change_callback,
                       bool is_foreground,
                       update_client::Callback callback) override {
-    NOTREACHED_IN_MIGRATION();
+    NOTREACHED();
   }
 
   bool GetCrxUpdateState(

extensions/browser/user_script_manager.cc

@@ -75,8 +75,7 @@ EmbedderUserScriptLoader* UserScriptManager::GetUserScriptLoaderForEmbedder(
     case mojom::HostID::HostType::kExtensions:
       break;
   }
-  NOTREACHED_IN_MIGRATION();
-  return nullptr;
+  NOTREACHED();
 }
 
 void UserScriptManager::SetUserScriptSourceEnabledForExtensions(

extensions/browser/warning_set.cc

@@ -175,8 +175,7 @@ std::string Warning::GetLocalizedMessage(const ExtensionSet* extensions) const {
       return l10n_util::GetStringFUTF8(message_id_, final_parameters[0],
           final_parameters[1], final_parameters[2], final_parameters[3]);
     default:
-      NOTREACHED_IN_MIGRATION();
-      return std::string();
+      NOTREACHED();
   }
 }
 

extensions/common/api/messaging/messaging_endpoint.cc

@@ -45,8 +45,7 @@ const char* ConvertMessagingSourceTypeToString(
     case MessagingEndpoint::Type::kNativeApp:
       return "NativeApp";
   }
-  NOTREACHED_IN_MIGRATION();
-  return "<unrecognized enum value>";
+  NOTREACHED();
 }
 
 base::debug::ScopedCrashKeyString CreateExtensionIdOrNativeAppNameScopedKey(
@@ -66,10 +65,7 @@ base::debug::ScopedCrashKeyString CreateExtensionIdOrNativeAppNameScopedKey(
           endpoint.native_app_name.value_or("<base::nullopt>"));
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return base::debug::ScopedCrashKeyString(
-      GetMessagingSourceExtensionIdCrashKey(),
-      endpoint.extension_id.value_or("<unrecognized MessagingEndpoint::Type>"));
+  NOTREACHED();
 }
 
 }  // namespace

extensions/common/api/scripts_internal/script_serialization.cc

@@ -162,8 +162,7 @@ std::unique_ptr<UserScript> ParseSerializedUserScript(
           serialized_script.id, UserScript::kManifestContentScriptPrefix);
       break;
     case api::scripts_internal::Source::kNone:
-      NOTREACHED_IN_MIGRATION();  // This should have been caught by our
-                                  // parsing.
+      NOTREACHED();  // This should have been caught by our parsing.
   }
 
   if (!source_matches_id) {

extensions/common/event_filter.cc

@@ -156,9 +156,7 @@ std::set<EventFilter::MatcherID> EventFilter::MatchEvent(
   for (const auto& id_key : matching_condition_set_ids) {
     auto matcher_id = condition_set_id_to_event_matcher_id_.find(id_key);
     if (matcher_id == condition_set_id_to_event_matcher_id_.end()) {
-      NOTREACHED_IN_MIGRATION()
-          << "id not found in condition set map (" << id_key << ")";
-      continue;
+      NOTREACHED() << "id not found in condition set map (" << id_key << ")";
     }
     MatcherID id = matcher_id->second;
     auto matcher_entry = matcher_map.find(id);

extensions/common/extension.cc

@@ -177,8 +177,7 @@ bool ComputeExtensionID(const base::Value::Dict& manifest,
   // reloading the extension.
   *extension_id = crx_file::id_util::GenerateIdForPath(path);
   if (extension_id->empty()) {
-    NOTREACHED_IN_MIGRATION() << "Could not create ID from path.";
-    return false;
+    NOTREACHED() << "Could not create ID from path.";
   }
   return true;
 }

extensions/common/extension_l10n_util.cc

@@ -457,8 +457,7 @@ bool GetValidLocales(const base::FilePath& locale_path,
   while (!(locale_folder = locales.Next()).empty()) {
     std::string locale_name = locale_folder.BaseName().MaybeAsASCII();
     if (locale_name.empty()) {
-      NOTREACHED_IN_MIGRATION();
-      continue;  // Not ASCII.
+      NOTREACHED();  // Not ASCII.
     }
     if (!AddLocale(
             chrome_locales, locale_folder, locale_name, valid_locales, error)) {
@@ -549,8 +548,7 @@ bool ShouldSkipValidation(const base::FilePath& locales_path,
   // '.svn' directories.
   base::FilePath relative_path;
   if (!locales_path.AppendRelativePath(locale_path, &relative_path)) {
-    NOTREACHED_IN_MIGRATION();
-    return true;
+    NOTREACHED();
   }
   std::string subdir = relative_path.MaybeAsASCII();
   if (subdir.empty())

extensions/common/extensions_client.cc

@@ -64,7 +64,7 @@ std::unique_ptr<FeatureProvider> ExtensionsClient::CreateFeatureProvider(
   } else if (name == "behavior") {
     method = &ExtensionsAPIProvider::AddBehaviorFeatures;
   } else {
-    NOTREACHED_IN_MIGRATION();
+    NOTREACHED();
   }
   for (const auto& api_provider : api_providers_)
     ((*api_provider).*method)(feature_provider.get());

extensions/common/features/simple_feature.cc

@@ -98,10 +98,9 @@ std::string GetDisplayName(Manifest::Type type) {
     case Manifest::TYPE_CHROMEOS_SYSTEM_EXTENSION:
       return "chromeos system extension";
     case Manifest::NUM_LOAD_TYPES:
-      NOTREACHED_IN_MIGRATION();
+      NOTREACHED();
   }
-  NOTREACHED_IN_MIGRATION();
-  return "";
+  NOTREACHED();
 }
 
 // Gets a human-readable name for the given context type, suitable for giving
@@ -135,8 +134,7 @@ std::string GetDisplayName(mojom::ContextType context) {
     case mojom::ContextType::kUserScript:
       return "user script";
   }
-  NOTREACHED_IN_MIGRATION();
-  return "";
+  NOTREACHED();
 }
 
 std::string GetDisplayName(mojom::FeatureSessionType session_type) {
@@ -406,8 +404,7 @@ std::string SimpleFeature::GetAvailabilityMessage(
                                 name().c_str());
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return std::string();
+  NOTREACHED();
 }
 
 Feature::Availability SimpleFeature::CreateAvailability(
@@ -515,8 +512,7 @@ bool SimpleFeature::MatchesManifestLocation(
     case SimpleFeature::UNPACKED_LOCATION:
       return Manifest::IsUnpackedLocation(manifest_location);
   }
-  NOTREACHED_IN_MIGRATION();
-  return false;
+  NOTREACHED();
 }
 
 bool SimpleFeature::MatchesSessionTypes(

extensions/common/mojom/channel_mojom_traits.h

@@ -27,8 +27,7 @@ struct EnumTraits<extensions::mojom::Channel, version_info::Channel> {
       case version_info::Channel::STABLE:
         return extensions::mojom::Channel::kStable;
     }
-    NOTREACHED_IN_MIGRATION();
-    return extensions::mojom::Channel::kUnknown;
+    NOTREACHED();
   }
 
   static bool FromMojom(extensions::mojom::Channel input,
@@ -50,9 +49,7 @@ struct EnumTraits<extensions::mojom::Channel, version_info::Channel> {
         *out = version_info::Channel::STABLE;
         return true;
     }
-    NOTREACHED_IN_MIGRATION();
-    *out = version_info::Channel::UNKNOWN;
-    return false;
+    NOTREACHED();
   }
 };
 

extensions/common/utils/extension_types_utils.cc

@@ -19,8 +19,7 @@ mojom::RunLocation ConvertRunLocation(api::extension_types::RunAt run_at) {
       return mojom::RunLocation::kDocumentStart;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return mojom::RunLocation::kDocumentIdle;
+  NOTREACHED();
 }
 
 api::extension_types::RunAt ConvertRunLocationForAPI(
@@ -40,8 +39,7 @@ api::extension_types::RunAt ConvertRunLocationForAPI(
       break;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return api::extension_types::RunAt::kDocumentIdle;
+  NOTREACHED();
 }
 
 mojom::ExecutionWorld ConvertExecutionWorld(
@@ -72,8 +70,7 @@ api::extension_types::ExecutionWorld ConvertExecutionWorldForAPI(
       return api::extension_types::ExecutionWorld::kUserScript;
   }
 
-  NOTREACHED_IN_MIGRATION();
-  return api::extension_types::ExecutionWorld::kIsolated;
+  NOTREACHED();
 }
 
 }  // namespace extensions

extensions/renderer/api/app_window_custom_bindings.cc

@@ -81,23 +81,20 @@ void AppWindowCustomBindings::GetFrame(
 void AppWindowCustomBindings::ResumeParser(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   if (args.Length() != 1 || !args[0]->IsString()) {
-    NOTREACHED_IN_MIGRATION();
-    return;
+    NOTREACHED();
   }
 
   content::RenderFrame* app_frame =
       ExtensionFrameHelper::FindFrameFromFrameTokenString(context()->isolate(),
                                                           args[0]);
   if (!app_frame) {
-    NOTREACHED_IN_MIGRATION();
-    return;
+    NOTREACHED();
   }
 
   blink::WebDocumentLoader* loader =
       app_frame->GetWebFrame()->GetDocumentLoader();
   if (!loader) {
-    NOTREACHED_IN_MIGRATION();
-    return;
+    NOTREACHED();
   }
 
   loader->ResumeParser();

extensions/renderer/api/automation/automation_api_converters.cc

@@ -87,8 +87,7 @@ api::automation::EventType AXEventToAutomationEventType(
       api::automation::EventType automation_event_type =
           api::automation::ParseEventType(val);
       if (automation_event_type == api::automation::EventType::kNone) {
-        NOTREACHED_IN_MIGRATION()
-            << "Missing mapping from ax::mojom::Event: " << val;
+        NOTREACHED() << "Missing mapping from ax::mojom::Event: " << val;
       }
 
       enum_map->emplace_back(automation_event_type);
@@ -114,8 +113,8 @@ api::automation::EventType AXGeneratedEventToAutomationEventType(
       api::automation::EventType automation_event_type =
           api::automation::ParseEventType(val);
       if (automation_event_type == api::automation::EventType::kNone) {
-        NOTREACHED_IN_MIGRATION()
-            << "Missing mapping from ui::AXEventGenerator::Event: " << val;
+        NOTREACHED() << "Missing mapping from ui::AXEventGenerator::Event: "
+                     << val;
       }
 
       enum_map->emplace_back(automation_event_type);

extensions/renderer/api/declarative_content_hooks_delegate.cc

@@ -222,8 +222,7 @@ void DeclarativeContentHooksDelegate::HandleCall(
   v8::Local<v8::Object> this_object = info.This();
   if (this_object.IsEmpty()) {
     // Crazy script (e.g. declarativeContent.Foo.apply(null, args);).
-    NOTREACHED_IN_MIGRATION();
-    return;
+    NOTREACHED();
   }
 
   // TODO(devlin): Find a way to use APISignature here? It's a little awkward

extensions/renderer/api/dom_hooks_delegate.cc

@@ -49,7 +49,7 @@ APIBindingHooks::RequestResult DOMHooksDelegate::HandleRequest(
     result.return_value =
         OpenOrClosedShadowRoot(script_context, *parse_result.arguments);
   } else {
-    NOTREACHED_IN_MIGRATION();
+    NOTREACHED();
   }
 
   return result;