[Bookmark suggestions] Remove an obsolete pref entry

components/ntp_snippets/bookmarks/bookmark_suggestions_provider.cc

Index: components/ntp_snippets/bookmarks/bookmark_suggestions_provider.cc
diff --git a/components/ntp_snippets/bookmarks/bookmark_suggestions_provider.cc b/components/ntp_snippets/bookmarks/bookmark_suggestions_provider.cc
index 436e8bcee05591fd06b15d27983bbd40e3239477..0930a3215b67fbfc1a49264d5ce32693a3c0e685 100644
--- a/components/ntp_snippets/bookmarks/bookmark_suggestions_provider.cc
+++ b/components/ntp_snippets/bookmarks/bookmark_suggestions_provider.cc
@@ -18,9 +18,6 @@
 #include "components/ntp_snippets/category.h"
 #include "components/ntp_snippets/content_suggestion.h"
 #include "components/ntp_snippets/features.h"
-#include "components/ntp_snippets/pref_names.h"
-#include "components/prefs/pref_registry_simple.h"
-#include "components/prefs/pref_service.h"
 #include "components/strings/grit/components_strings.h"
 #include "components/variations/variations_associated_data.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -41,10 +38,6 @@ const char* kMaxBookmarkAgeInDaysParamName = "bookmarks_max_age_in_days";
 const char* kConsiderDesktopVisitsParamName =
     "bookmarks_consider_desktop_visits";
 
-// TODO(treib,jkrcal): Remove this after M57.
-const char kDeprecatedBookmarksFirstM54StartPref[] =
-    "ntp_suggestions.bookmarks.first_M54_start";
-
 // Any bookmark created or visited after this time will be considered recent.
 // Note that bookmarks can be shown that do not meet this threshold.
 base::Time GetThresholdTime() {
@@ -71,8 +64,7 @@ bool AreDesktopVisitsConsidered() {
 
 BookmarkSuggestionsProvider::BookmarkSuggestionsProvider(
     ContentSuggestionsProvider::Observer* observer,
-    bookmarks::BookmarkModel* bookmark_model,
-    PrefService* pref_service)
+    bookmarks::BookmarkModel* bookmark_model)
     : ContentSuggestionsProvider(observer),
       category_status_(CategoryStatus::AVAILABLE_LOADING),
       provided_category_(
@@ -82,7 +74,6 @@ BookmarkSuggestionsProvider::BookmarkSuggestionsProvider(
       end_of_list_last_visit_date_(GetThresholdTime()),
       consider_bookmark_visits_from_desktop_(AreDesktopVisitsConsidered()) {
   observer->OnCategoryStatusChanged(this, provided_category_, category_status_);
-  pref_service->ClearPref(kDeprecatedBookmarksFirstM54StartPref);
   bookmark_model_->AddObserver(this);
   FetchBookmarks();
 }
@@ -91,12 +82,6 @@ BookmarkSuggestionsProvider::~BookmarkSuggestionsProvider() {
   bookmark_model_->RemoveObserver(this);
 }
 
-// static
-void BookmarkSuggestionsProvider::RegisterProfilePrefs(
-    PrefRegistrySimple* registry) {
-  registry->RegisterInt64Pref(kDeprecatedBookmarksFirstM54StartPref, 0);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // Private methods