Prefetch: Remove PrefetchBrowsingDataRemoval

This flag was introduced half-years ago only for emergency kill switch
(crrev.com/c/6406438) preventing from a potential crash related to
crbug.com/404703517 (see #comment25 for more context). Now we can
eliminate this safely.

Bug: 40262310
Change-Id: Iae299ad8a9ade0922609603119aa41a3886f7980
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7037133
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Reviewed-by: Steven Wei <stevenwei@microsoft.com>
Commit-Queue: Taiyo Mizuhashi <taiyo@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1535831}
diff --git a/content/browser/browsing_data/browsing_data_remover_impl.cc b/content/browser/browsing_data/browsing_data_remover_impl.cc
index 3004feb..9f3805b1 100644
--- a/content/browser/browsing_data/browsing_data_remover_impl.cc
+++ b/content/browser/browsing_data/browsing_data_remover_impl.cc
@@ -648,8 +648,7 @@
 
   // Clears the Prefetch Cache as part of Clear-Site-Data prefetchCache header
   // and Browsing Data Cache Removal.
-  if ((remove_mask & (DATA_TYPE_PREFETCH_CACHE | DATA_TYPE_CACHE)) &&
-      base::FeatureList::IsEnabled(features::kPrefetchBrowsingDataRemoval)) {
+  if ((remove_mask & (DATA_TYPE_PREFETCH_CACHE | DATA_TYPE_CACHE))) {
     if (auto* prefetch_service =
             BrowserContextImpl::From(browser_context_)->GetPrefetchService()) {
       auto storage_key_filter = filter_builder->BuildStorageKeyFilter();
diff --git a/content/browser/browsing_data/browsing_data_remover_impl_browsertest.cc b/content/browser/browsing_data/browsing_data_remover_impl_browsertest.cc
index b6b1fd3..12037bb 100644
--- a/content/browser/browsing_data/browsing_data_remover_impl_browsertest.cc
+++ b/content/browser/browsing_data/browsing_data_remover_impl_browsertest.cc
@@ -1054,10 +1054,6 @@
 class BrowsingDataRemoverImplPrefetchBrowserTest
     : public BrowsingDataRemoverImplBrowserTest {
  public:
-  BrowsingDataRemoverImplPrefetchBrowserTest() {
-    feature_list_.InitAndEnableFeature(features::kPrefetchBrowsingDataRemoval);
-  }
-
   void StartPrefetch(const GURL& url, Shell* shell) {
     auto* prefetch_document_manager =
         PrefetchDocumentManager::GetOrCreateForCurrentDocument(
@@ -1076,9 +1072,6 @@
   }
 
   ~BrowsingDataRemoverImplPrefetchBrowserTest() override = default;
-
- private:
-  base::test::ScopedFeatureList feature_list_;
 };
 
 IN_PROC_BROWSER_TEST_F(BrowsingDataRemoverImplPrefetchBrowserTest,
diff --git a/content/browser/preloading/prefetch/prefetch_features.cc b/content/browser/preloading/prefetch/prefetch_features.cc
index add1e33..4853f889 100644
--- a/content/browser/preloading/prefetch/prefetch_features.cc
+++ b/content/browser/preloading/prefetch/prefetch_features.cc
@@ -58,8 +58,6 @@
              browser_context);
 }
 
-BASE_FEATURE(kPrefetchBrowsingDataRemoval, base::FEATURE_ENABLED_BY_DEFAULT);
-
 BASE_FEATURE(kPrefetchScheduler, base::FEATURE_DISABLED_BY_DEFAULT);
 const base::FeatureParam<bool> kPrefetchSchedulerProgressSyncBestEffort{
     &kPrefetchScheduler, "kPrefetchSchedulerProgressSyncBestEffort", true};
diff --git a/content/browser/preloading/prefetch/prefetch_features.h b/content/browser/preloading/prefetch/prefetch_features.h
index a5b937f7..749f2bc 100644
--- a/content/browser/preloading/prefetch/prefetch_features.h
+++ b/content/browser/preloading/prefetch/prefetch_features.h
@@ -83,10 +83,6 @@
 CONTENT_EXPORT BASE_DECLARE_FEATURE(kPrefetchServiceWorker);
 bool IsPrefetchServiceWorkerEnabled(content::BrowserContext* browser_context);
 
-// If enabled, prefetch caches are cleared when browsing data removal. Please
-// see crbug.com/40262310 for more details.
-CONTENT_EXPORT BASE_DECLARE_FEATURE(kPrefetchBrowsingDataRemoval);
-
 // Replace current prefetch queue with a new queue and scheduler, which allows
 // prioritization, concurrent prefetches, bursting.
 //