Wire up download attribution enable finch experiment

chrome/browser/ui/tab_helpers.cc

Index: chrome/browser/ui/tab_helpers.cc
diff --git a/chrome/browser/ui/tab_helpers.cc b/chrome/browser/ui/tab_helpers.cc
index 74e762cf20c2e4276b868ce290ef36326b2ee490..0ef2975bb76e98124d06b83ce8a0cd2179f3b97a 100644
--- a/chrome/browser/ui/tab_helpers.cc
+++ b/chrome/browser/ui/tab_helpers.cc
@@ -77,6 +77,7 @@
 #else
 #include "chrome/browser/banners/app_banner_manager_desktop.h"
 #include "chrome/browser/plugins/plugin_observer.h"
+#include "chrome/browser/safe_browsing/safe_browsing_navigation_observer.h"
 #include "chrome/browser/safe_browsing/safe_browsing_tab_observer.h"
 #include "chrome/browser/thumbnails/thumbnail_tab_helper.h"
 #include "chrome/browser/ui/bookmarks/bookmark_tab_helper.h"
@@ -228,6 +229,8 @@ void TabHelpers::AttachTabHelpers(WebContents* web_contents) {
   PluginObserver::CreateForWebContents(web_contents);
   SadTabHelper::CreateForWebContents(web_contents);
   safe_browsing::SafeBrowsingTabObserver::CreateForWebContents(web_contents);
+  safe_browsing::SafeBrowsingNavigationObserver::MaybeCreateForWebContents(
+      web_contents);
   TabContentsSyncedTabDelegate::CreateForWebContents(web_contents);
   TabDialogs::CreateForWebContents(web_contents);
   ThumbnailTabHelper::CreateForWebContents(web_contents);