Clean up DownloadAttribution Finch experiments

chrome/browser/safe_browsing/safe_browsing_service.cc

Index: chrome/browser/safe_browsing/safe_browsing_service.cc
diff --git a/chrome/browser/safe_browsing/safe_browsing_service.cc b/chrome/browser/safe_browsing/safe_browsing_service.cc
index 3fafd011bc34dd2983ddc63ead74be952595a701..4c44cb2a04994e00c91afa1379e10e86de1e5b16 100644
--- a/chrome/browser/safe_browsing/safe_browsing_service.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_service.cc
@@ -324,10 +324,7 @@ void SafeBrowsingService::Initialize() {
     database_manager_ = CreateDatabaseManager();
   }
 
-  if (base::FeatureList::IsEnabled(
-    SafeBrowsingNavigationObserverManager::kDownloadAttribution)) {
-    navigation_observer_manager_ = new SafeBrowsingNavigationObserverManager();
-  }
+  navigation_observer_manager_ = new SafeBrowsingNavigationObserverManager();
 
   services_delegate_->Initialize(v4_enabled_);
   services_delegate_->InitializeCsdService(url_request_context_getter_.get());