Replace the GURL referrer field of OpenURLParams with a content::Referrer

chrome/browser/download/download_shelf_context_menu.cc

Index: chrome/browser/download/download_shelf_context_menu.cc
diff --git a/chrome/browser/download/download_shelf_context_menu.cc b/chrome/browser/download/download_shelf_context_menu.cc
index 65807aac74660da78946e2a31bf953712e5ecd7b..e30ab2b00afeaa41bb1cb8a719e05ce3442656c0 100644
--- a/chrome/browser/download/download_shelf_context_menu.cc
+++ b/chrome/browser/download/download_shelf_context_menu.cc
@@ -111,7 +111,7 @@ void DownloadShelfContextMenu::ExecuteCommand(int command_id) {
       DCHECK(browser && browser->is_type_tabbed());
       GURL learn_more_url(chrome::kDownloadScanningLearnMoreURL);
       OpenURLParams params(google_util::AppendGoogleLocaleParam(learn_more_url),
-                           GURL(), NEW_FOREGROUND_TAB,
+                           content::Referrer(), NEW_FOREGROUND_TAB,
                            content::PAGE_TRANSITION_TYPED, false);
       browser->OpenURL(params);
       break;