Do not removed shields settings with empty primary pattern.

browser/browsing_data/DEPS

@@ -1,3 +1,4 @@
 include_rules = [
   "+brave/components/content_settings/core/browser",
+  "+brave/components/content_settings/core/common",
 ]

browser/browsing_data/brave_browsing_data_remover_delegate.cc

@@ -5,14 +5,13 @@
 
 #include "brave/browser/browsing_data/brave_browsing_data_remover_delegate.h"
 
-#include <memory>
 #include <utility>
+#include <vector>
 
+#include "base/containers/flat_map.h"
 #include "brave/browser/ai_chat/ai_chat_service_factory.h"
 #include "brave/browser/brave_news/brave_news_controller_factory.h"
 #include "brave/components/ai_chat/core/browser/ai_chat_service.h"
-#include "brave/components/ai_chat/core/browser/utils.h"
-#include "brave/components/ai_chat/core/common/features.h"
 #include "brave/components/brave_news/browser/brave_news_controller.h"
 #include "brave/components/content_settings/core/browser/brave_content_settings_pref_provider.h"
 #include "brave/components/content_settings/core/browser/brave_content_settings_utils.h"
@@ -25,6 +24,47 @@
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "content/public/browser/browsing_data_remover.h"
 
+namespace {
+
+class ContentSettingsDefaultsKeeper {
+ public:
+  explicit ContentSettingsDefaultsKeeper(Profile* profile) : profile_(profile) {
+    auto* map = HostContentSettingsMapFactory::GetForProfile(profile_);
+
+    const auto shields_content_types =
+        content_settings::GetShieldsContentSettingsTypes();
+    for (const auto content_type : shields_content_types) {
+      ContentSettingsForOneType settings =
+          map->GetSettingsForOneType(content_type);
+      for (const auto& setting : settings) {
+        if (setting.source !=
+                content_settings::ProviderType::kDefaultProvider &&
+            setting.primary_pattern.MatchesAllHosts()) {
+          defaults_[content_type].push_back(setting);
+        }
+      }
+    }
+  }
+
+  ~ContentSettingsDefaultsKeeper() {
+    auto* map = HostContentSettingsMapFactory::GetForProfile(profile_);
+    for (auto&& [content_type, settings] : defaults_) {
+      for (auto&& setting : settings) {
+        map->SetWebsiteSettingCustomScope(
+            setting.primary_pattern, setting.secondary_pattern, content_type,
+            std::move(setting.setting_value));
+      }
+    }
+  }
+
+ private:
+  raw_ptr<Profile> profile_ = nullptr;
+  base::flat_map<ContentSettingsType, std::vector<ContentSettingPatternSource>>
+      defaults_;
+};
+
+}  // namespace
+
 BraveBrowsingDataRemoverDelegate::BraveBrowsingDataRemoverDelegate(
     content::BrowserContext* browser_context)
     : ChromeBrowsingDataRemoverDelegate(browser_context),
@@ -39,6 +79,8 @@ void BraveBrowsingDataRemoverDelegate::RemoveEmbedderData(
     content::BrowsingDataFilterBuilder* filter_builder,
     uint64_t origin_type_mask,
     base::OnceCallback<void(/*failed_data_types=*/uint64_t)> callback) {
+  ContentSettingsDefaultsKeeper default_values_keeper(profile_);
+
   ChromeBrowsingDataRemoverDelegate::RemoveEmbedderData(
       delete_begin, delete_end, remove_mask, filter_builder, origin_type_mask,
       std::move(callback));

browser/browsing_data/brave_browsing_data_remover_delegate_unittest.cc

@@ -6,17 +6,16 @@
 #include "brave/browser/browsing_data/brave_browsing_data_remover_delegate.h"
 
 #include <memory>
-#include <string>
-#include <utility>
 
-#include "base/functional/bind.h"
+#include "base/test/bind.h"
 #include "brave/components/brave_shields/content/browser/brave_shields_util.h"
-#include "brave/components/brave_shields/core/common/brave_shield_constants.h"
 #include "brave/components/content_settings/core/browser/brave_content_settings_utils.h"
+#include "chrome/browser/browsing_data/chrome_browsing_data_remover_constants.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/test/base/testing_profile.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/common/content_settings_types.h"
+#include "content/public/browser/browsing_data_filter_builder.h"
 #include "content/public/test/browser_task_environment.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/gurl.h"
@@ -85,3 +84,31 @@ TEST_F(BraveBrowsingDataRemoverDelegateTest, ShieldsSettingsClearTest) {
   delegate()->ClearShieldsSettings(k1DaysOld, kNow);
   EXPECT_EQ(start_count, GetShieldsSettingsCount());
 }
+
+TEST_F(BraveBrowsingDataRemoverDelegateTest, ShieldsSettingsKeepDefaults) {
+  brave_shields::SetAdControlType(map(), brave_shields::ControlType::BLOCK,
+                                  GURL());
+  brave_shields::SetCosmeticFilteringControlType(
+      map(), brave_shields::ControlType::BLOCK, GURL());
+
+  EXPECT_EQ(brave_shields::DomainBlockingType::kAggressive,
+            brave_shields::GetDomainBlockingType(map(), GURL()));
+  auto filter_builder = content::BrowsingDataFilterBuilder::Create(
+      content::BrowsingDataFilterBuilder::Mode::kPreserve);
+  base::RunLoop run_loop;
+  profile()->GetBrowsingDataRemoverDelegate()->RemoveEmbedderData(
+      /*delete_begin=*/base::Time::Min(),
+      /*delete_end=*/base::Time::Max(),
+      /*remove_mask=*/
+      chrome_browsing_data_remover::DATA_TYPE_CONTENT_SETTINGS,
+      filter_builder.get(),
+      /*origin_type_mask=*/1,
+      base::BindLambdaForTesting([&run_loop](uint64_t failed_data_types) {
+        EXPECT_EQ(failed_data_types, 0U);
+        run_loop.Quit();
+      }));
+  run_loop.Run();
+
+  EXPECT_EQ(brave_shields::DomainBlockingType::kAggressive,
+            brave_shields::GetDomainBlockingType(map(), GURL()));
+}

browser/browsing_data/sources.gni

@@ -16,6 +16,7 @@ brave_browser_browsing_data_deps = [
   "//base",
   "//brave/browser/ai_chat",
   "//brave/components/ai_chat/core/browser",
+  "//brave/components/content_settings/core/common",
   "//chrome/browser:browser_process",
   "//chrome/browser/browsing_data:constants",
   "//chrome/browser/profiles:profile",

chromium_src/chrome/browser/browsing_data/counters/DEPS

@@ -0,0 +1,3 @@
+include_rules = [
+  "+brave/components/content_settings/core/browser",
+]

chromium_src/chrome/browser/browsing_data/counters/site_settings_counter.cc

@@ -0,0 +1,50 @@
+/* Copyright (c) 2025 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "chrome/browser/browsing_data/counters/site_settings_counter.h"
+
+#include "brave/components/content_settings/core/browser/brave_content_settings_utils.h"
+
+namespace {
+
+int GetBraveShieldsDefaultsCount(base::Time period_start,
+                                 base::Time period_end,
+                                 HostContentSettingsMap* map) {
+  int empty_host_pattern = 0;
+  auto iterate_content_settings_list =
+      [&](ContentSettingsType content_type,
+          const ContentSettingsForOneType& content_settings_list) {
+        for (const auto& content_setting : content_settings_list) {
+          if (content_settings::GetSettingSourceFromProviderType(
+                  content_setting.source) ==
+                  content_settings::SettingSource::kUser &&
+              content_setting.source !=
+                  content_settings::ProviderType::kDefaultProvider) {
+            base::Time last_modified = content_setting.metadata.last_modified();
+            if (last_modified >= period_start && last_modified < period_end) {
+              if (content_setting.primary_pattern.GetHost().empty()) {
+                empty_host_pattern++;
+              }
+            }
+          }
+        }
+      };
+
+  for (const auto type : content_settings::GetShieldsContentSettingsTypes()) {
+    iterate_content_settings_list(type, map->GetSettingsForOneType(type));
+  }
+
+  return empty_host_pattern;
+}
+
+}  // namespace
+
+#define ReportResult(...)                                  \
+  ReportResult(__VA_ARGS__ - GetBraveShieldsDefaultsCount( \
+                                 period_start, period_end, map_.get()))
+
+#include "src/chrome/browser/browsing_data/counters/site_settings_counter.cc"
+
+#undef ReportResult

components/content_settings/core/browser/brave_content_settings_utils.h

@@ -10,7 +10,6 @@
 #include <string>
 #include <vector>
 
-#include "base/time/time.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/content_settings/core/common/content_settings_constraints.h"
 #include "components/content_settings/core/common/content_settings_types.h"

test/BUILD.gn

@@ -282,6 +282,7 @@ test("brave_unit_tests") {
     "//chrome:resources",
     "//chrome:strings",
     "//chrome/app:command_ids",
+    "//chrome/browser/browsing_data:constants",
     "//chrome/browser/content_settings:content_settings_factory",
     "//chrome/browser/favicon",
     "//chrome/browser/permissions",