Omit save_password_infobar.cc from the build when unused

chrome/browser/ui/views/infobars/save_password_infobar.cc

Index: chrome/browser/ui/views/infobars/save_password_infobar.cc
diff --git a/chrome/browser/ui/views/infobars/save_password_infobar.cc b/chrome/browser/ui/views/infobars/save_password_infobar.cc
index 30ea9b53fd3c7e9e021a488fab294342a438f51b..86d04503e4f6edbbf850cc73482edb4ff485b56b 100644
--- a/chrome/browser/ui/views/infobars/save_password_infobar.cc
+++ b/chrome/browser/ui/views/infobars/save_password_infobar.cc
@@ -5,6 +5,8 @@
 #include "chrome/browser/password_manager/save_password_infobar_delegate.h"
 #include "chrome/browser/ui/views/infobars/confirm_infobar.h"
 
+// TODO(tapted): Delete this file when Mac uses the password bubble by default.
+
 scoped_ptr<infobars::InfoBar> CreateSavePasswordInfoBar(
     scoped_ptr<SavePasswordInfoBarDelegate> delegate) {
   return make_scoped_ptr(new ConfirmInfoBar(delegate.Pass()));