Makes sync code persist the date the node was added. I'm hoping this covers

chrome/browser/bookmarks/bookmark_model.cc

Index: chrome/browser/bookmarks/bookmark_model.cc
diff --git a/chrome/browser/bookmarks/bookmark_model.cc b/chrome/browser/bookmarks/bookmark_model.cc
index 84b41c66575b007279075df67024539ccf887224..94d32a05dcf64a10e5c179bb0e185499760a0a5e 100644
--- a/chrome/browser/bookmarks/bookmark_model.cc
+++ b/chrome/browser/bookmarks/bookmark_model.cc
@@ -468,7 +468,9 @@ const BookmarkNode* BookmarkModel::AddURLWithCreationTime(
 
   bool was_bookmarked = IsBookmarked(url);
 
-  SetDateFolderModified(parent, creation_time);
+  // Syncing may result in dates older than the last modified date.
+  if (creation_time > parent->date_folder_modified())
+    SetDateFolderModified(parent, creation_time);
 
   BookmarkNode* new_node = new BookmarkNode(generate_next_node_id(), url);
   new_node->SetTitle(title);