Add timestamp support to the Previews infobar

components/infobars/core/infobar_delegate.cc

Index: components/infobars/core/infobar_delegate.cc
diff --git a/components/infobars/core/infobar_delegate.cc b/components/infobars/core/infobar_delegate.cc
index c3c0c97baf10cd4b8061c582ec770e4d27f207a3..fb633c01d5be8a6f65075e3033566f82a21b007d 100644
--- a/components/infobars/core/infobar_delegate.cc
+++ b/components/infobars/core/infobar_delegate.cc
@@ -101,6 +101,10 @@ PopupBlockedInfoBarDelegate* InfoBarDelegate::AsPopupBlockedInfoBarDelegate() {
   return nullptr;
 }
 
+PreviewsInfoBarDelegate* InfoBarDelegate::AsPreviewsInfoBarDelegate() {
+  return nullptr;
+}
+
 RegisterProtocolHandlerInfoBarDelegate*
     InfoBarDelegate::AsRegisterProtocolHandlerInfoBarDelegate() {
   return nullptr;