Documented that the new nodes at the root aren't meant to sync.

chrome/browser/sync/glue/bookmark_change_processor.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/sync/glue/bookmark_change_processor.h"
 
 #include <map>
 #include <stack>
 #include <vector>
 
@@ skipping 131 matching lines @@
     syncer::WriteTransaction trans(FROM_HERE, share_handle(), &new_version);
 
     RemoveAllChildNodes(&trans, bookmark_model_->bookmark_bar_node()->id());
     RemoveAllChildNodes(&trans, bookmark_model_->other_node()->id());
     // Remove mobile bookmarks node only if it is present.
     const int64 mobile_bookmark_id = bookmark_model_->mobile_node()->id();
     if (model_associator_->GetSyncIdFromChromeId(mobile_bookmark_id) !=
             syncer::kInvalidId) {
       RemoveAllChildNodes(&trans, bookmark_model_->mobile_node()->id());
     }
+    // Note: the root node may have additional extra nodes. Currently none of
+    // them are meant to sync.
   }
 
   // Don't need to update versions of deleted nodes.
   UpdateTransactionVersion(new_version, bookmark_model_,
                            std::vector<const BookmarkNode*>());
 }
 
 void BookmarkChangeProcessor::RemoveAllChildNodes(
     syncer::WriteTransaction* trans, const int64& topmost_node_id) {
   syncer::WriteNode topmost_node(trans);
@@ skipping 674 matching lines @@
     sync_pb::BookmarkSpecifics updated_specifics(
         sync_node->GetBookmarkSpecifics());
     updated_specifics.set_favicon(favicon_bytes->front(),
                                   favicon_bytes->size());
     updated_specifics.set_icon_url(bookmark_node->icon_url().spec());
     sync_node->SetBookmarkSpecifics(updated_specifics);
   }
 }
 
 }  // namespace browser_sync