[Bookmark suggestions] Remove an obsolete pref entry

components/ntp_snippets/bookmarks/bookmark_suggestions_provider.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/ntp_snippets/bookmarks/bookmark_suggestions_provider.h"
 
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "components/ntp_snippets/bookmarks/bookmark_last_visit_utils.h"
 #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"
 #include "ui/gfx/image/image.h"
 
 using bookmarks::BookmarkModel;
 using bookmarks::BookmarkNode;
 
 namespace ntp_snippets {
 
 namespace {
 
 const int kMaxBookmarks = 10;
 const int kMaxBookmarkAgeInDays = 42;
 
 const char* kMaxBookmarksParamName = "bookmarks_max_count";
 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() {
   return base::Time::Now() -
          base::TimeDelta::FromDays(variations::GetVariationParamByFeatureAsInt(
              ntp_snippets::kBookmarkSuggestionsFeature,
              kMaxBookmarkAgeInDaysParamName, kMaxBookmarkAgeInDays));
 }
 
 // The maximum number of suggestions ever provided.
 int GetMaxCount() {
   return variations::GetVariationParamByFeatureAsInt(
       ntp_snippets::kBookmarkSuggestionsFeature, kMaxBookmarksParamName,
       kMaxBookmarks);
 }
 
 bool AreDesktopVisitsConsidered() {
   return variations::GetVariationParamByFeatureAsBool(
       ntp_snippets::kBookmarkSuggestionsFeature,
       kConsiderDesktopVisitsParamName, false);
 }
 
 }  // namespace
 
 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_(
           Category::FromKnownCategory(KnownCategories::BOOKMARKS)),
       bookmark_model_(bookmark_model),
       fetch_requested_(false),
       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();
 }
 
 BookmarkSuggestionsProvider::~BookmarkSuggestionsProvider() {
   bookmark_model_->RemoveObserver(this);
 }
 
-// static
-void BookmarkSuggestionsProvider::RegisterProfilePrefs(
-    PrefRegistrySimple* registry) {
-  registry->RegisterInt64Pref(kDeprecatedBookmarksFirstM54StartPref, 0);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // Private methods
 
 CategoryStatus BookmarkSuggestionsProvider::GetCategoryStatus(
     Category category) {
   DCHECK_EQ(category, provided_category_);
   return category_status_;
 }
 
 CategoryInfo BookmarkSuggestionsProvider::GetCategoryInfo(Category category) {
@@ skipping 208 matching lines @@
 void BookmarkSuggestionsProvider::NotifyStatusChanged(
     CategoryStatus new_status) {
   if (category_status_ == new_status) {
     return;
   }
   category_status_ = new_status;
   observer()->OnCategoryStatusChanged(this, provided_category_, new_status);
 }
 
 }  // namespace ntp_snippets