remove legacy cosmetic filter migration code

browser/extensions/api/brave_shields_api.cc

@@ -131,22 +131,6 @@ void BraveShieldsHiddenClassIdSelectorsFunction::GetHiddenClassIdSelectorsOnUI(
   Respond(ArgumentList(std::move(selectors)));
 }
 
-ExtensionFunction::ResponseAction
-BraveShieldsMigrateLegacyCosmeticFiltersFunction::Run() {
-  std::unique_ptr<brave_shields::MigrateLegacyCosmeticFilters::Params> params(
-      brave_shields::MigrateLegacyCosmeticFilters::Params::Create(*args_));
-  EXTENSION_FUNCTION_VALIDATE(params.get());
-
-  const bool success =
-      g_brave_browser_process->ad_block_custom_filters_service()
-          ->MigrateLegacyCosmeticFilters(
-              params->legacy_filters.additional_properties);
-
-  auto callback_args = std::make_unique<base::ListValue>();
-  callback_args->Append(base::Value(success));
-  return RespondNow(ArgumentList(std::move(callback_args)));
-}
-
 ExtensionFunction::ResponseAction
 BraveShieldsAddSiteCosmeticFilterFunction::Run() {
   std::unique_ptr<brave_shields::AddSiteCosmeticFilter::Params> params(

browser/extensions/api/brave_shields_api.h

@@ -48,18 +48,6 @@ class BraveShieldsHiddenClassIdSelectorsFunction : public ExtensionFunction {
       std::unique_ptr<base::ListValue> selectors);
 };
 
-class BraveShieldsMigrateLegacyCosmeticFiltersFunction
-    : public ExtensionFunction {
- public:
-  DECLARE_EXTENSION_FUNCTION("braveShields.migrateLegacyCosmeticFilters",
-                             UNKNOWN)
-
- protected:
-  ~BraveShieldsMigrateLegacyCosmeticFiltersFunction() override {}
-
-  ResponseAction Run() override;
-};
-
 class BraveShieldsAddSiteCosmeticFilterFunction : public ExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("braveShields.addSiteCosmeticFilter", UNKNOWN)

common/extensions/api/brave_shields.json

@@ -140,35 +140,6 @@
           }
         ]
       },
-      {
-        "name": "migrateLegacyCosmeticFilters",
-        "type": "function",
-        "description": "Appends the provided legacy cosmetic filters to the custom filters of brave://adblock",
-        "parameters": [
-          {
-            "name": "legacyFilters",
-            "type": "object",
-            "description": "Mapping from hostnames with stored legacy cosmetic filter rules to the corresponding lists of rules",
-            "additionalProperties": {
-              "type": "array",
-              "items": {
-                "type": "string"
-              }
-            }
-          },
-          {
-            "type": "function",
-            "name": "callback",
-            "description": "Returns true if the filters were successfully stored, signifying that the old filters should be removed",
-            "parameters": [
-              {
-                "name": "success",
-                "type": "boolean"
-              }
-            ]
-          }
-        ]
-      },
       {
         "name": "addSiteCosmeticFilter",
         "type": "function",

components/brave_extension/extension/brave_extension/background/api/cosmeticFilterAPI.ts

@@ -71,29 +71,6 @@ export const applyAdblockCosmeticFilters = (tabId: number, frameId: number, url:
   })
 }
 
-// A very early implementation of cosmetic filtering used extension-local
-// storage to store CSS selectors of elements to apply hide rules to on a
-// per-site basis.
-//
-// If any of these legacy cosmetic filters are still present, this function
-// will migrate them to share the adblock-rust infrastructure used by the
-// custom filters engine from brave://adblock.
-const tryMigratingLegacyCosmeticFilters = () => {
-  chrome.storage.local.get('cosmeticFilterList', (storeData = {}) => {
-    if (storeData.cosmeticFilterList !== undefined) {
-      const cosmeticFilterList = storeData.cosmeticFilterList
-      console.error(JSON.stringify(cosmeticFilterList))
-      chrome.braveShields.migrateLegacyCosmeticFilters(cosmeticFilterList, (success) => {
-        if (success) {
-          chrome.storage.local.remove('cosmeticFilterList')
-        } else {
-          console.error('Legacy cosmetic filter migration failed!')
-        }
-      })
-    }
-  })
-}
-
 export const addSiteCosmeticFilter = (host: string, cssSelector: string) => {
   chrome.braveShields.addSiteCosmeticFilter(host, cssSelector)
 }
@@ -101,7 +78,3 @@ export const addSiteCosmeticFilter = (host: string, cssSelector: string) => {
 export const openFilterManagementPage = () => {
   chrome.braveShields.openFilterManagementPage()
 }
-
-// Attempt to run the legacy filters migration during brave_extension
-// initialization.
-tryMigratingLegacyCosmeticFilters()

components/brave_shields/browser/ad_block_custom_filters_service.cc

@@ -51,36 +51,6 @@ bool AdBlockCustomFiltersService::UpdateCustomFilters(
   return true;
 }
 
-bool AdBlockCustomFiltersService::MigrateLegacyCosmeticFilters(
-    const std::map<std::string, std::vector<std::string>> legacyFilters) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  PrefService* local_state = delegate()->local_state();
-  if (!local_state)
-    return false;
-  std::string filters_update =
-      local_state->GetString(prefs::kAdBlockCustomFilters);
-
-  filters_update +=
-      "\n\n! Filters migrated from "
-      "'Right click > Brave > Block element via selector'";
-  for (const auto& hostEntry : legacyFilters) {
-    const std::string& host = hostEntry.first;
-    const std::vector<std::string>& hostSelectors = hostEntry.second;
-
-    for (const auto& selector : hostSelectors) {
-      if (selector.empty()) {
-        continue;
-      }
-
-      const std::string rule = '\n' + host + "##" + selector;
-
-      filters_update += rule;
-    }
-  }
-
-  return UpdateCustomFilters(filters_update);
-}
-
 void AdBlockCustomFiltersService::UpdateCustomFiltersOnFileTaskRunner(
     const std::string& custom_filters) {
   DCHECK(GetTaskRunner()->RunsTasksInCurrentSequence());

components/brave_shields/browser/ad_block_custom_filters_service.h

@@ -28,8 +28,6 @@ class AdBlockCustomFiltersService : public AdBlockBaseService {
 
   std::string GetCustomFilters();
   bool UpdateCustomFilters(const std::string& custom_filters);
-  bool MigrateLegacyCosmeticFilters(
-      const std::map<std::string, std::vector<std::string>> legacyFilters);
 
  protected:
   bool Init() override;

components/definitions/chromel.d.ts

@@ -334,7 +334,6 @@ declare namespace chrome.braveShields {
   }
   const urlCosmeticResources: (url: string, callback: (resources: UrlSpecificResources) => void) => void
   const hiddenClassIdSelectors: (classes: string[], ids: string[], exceptions: string[], callback: (selectors: string[], forceHideSelectors: string[]) => void) => void
-  const migrateLegacyCosmeticFilters: (legacyFilters: any, callback: (success: boolean) => void) => void
   const addSiteCosmeticFilter: (origin: string, cssSelector: string) => void
   const openFilterManagementPage: () => void