Wire up download attribution enable finch experiment

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 d03c2e4637e38292ab6b1501386d272bc71ee20b..eafb8f1b42837b235832259d4c25d2f25cf5c6b1 100644
--- a/chrome/browser/safe_browsing/safe_browsing_service.cc
+++ b/chrome/browser/safe_browsing/safe_browsing_service.cc
@@ -28,6 +28,7 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/safe_browsing/ping_manager.h"
+#include "chrome/browser/safe_browsing/safe_browsing_navigation_observer_manager.h"
 #include "chrome/browser/safe_browsing/ui_manager.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_switches.h"
@@ -309,6 +310,11 @@ void SafeBrowsingService::Initialize() {
     database_manager_ = CreateDatabaseManager();
   }
 
+  if (base::FeatureList::IsEnabled(
+    SafeBrowsingNavigationObserverManager::kDownloadAttribution)) {
+    navigation_observer_manager_ = new SafeBrowsingNavigationObserverManager();
+  }
+
   services_delegate_->Initialize();
   services_delegate_->InitializeCsdService(url_request_context_getter_.get());
 
@@ -393,6 +399,11 @@ SafeBrowsingService::database_manager() const {
   return enabled_v4_only_ ? v4_local_database_manager() : database_manager_;
 }
 
+scoped_refptr<SafeBrowsingNavigationObserverManager>
+SafeBrowsingService::navigation_observer_manager() {
+  return navigation_observer_manager_;
+}
+
 SafeBrowsingProtocolManager* SafeBrowsingService::protocol_manager() const {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 #if defined(SAFE_BROWSING_DB_LOCAL)