Client-side changes to support retry GU.

sync/engine/download.h

Index: sync/engine/download.h
diff --git a/sync/engine/download.h b/sync/engine/download.h
index 5bc08d434e1bb9a8b868cc694070a2c3f4d529a2..f7dde0d32e831ed6769d3f3e23abb482e36f6b8e 100644
--- a/sync/engine/download.h
+++ b/sync/engine/download.h
@@ -75,6 +75,17 @@ SYNC_EXPORT_PRIVATE void BuildDownloadUpdatesForPollImpl(
     UpdateHandlerMap* update_handler_map,
     sync_pb::GetUpdatesMessage* get_updates);
 
+// Same as above except the update origin is RETRY.
+SYNC_EXPORT_PRIVATE void BuildDownloadUpdatesForRetry(
+    sessions::SyncSession* session,
+    bool create_mobile_bookmarks_folder,
+    ModelTypeSet request_types,
+    sync_pb::ClientToServerMessage* client_to_server_message);
+SYNC_EXPORT_PRIVATE void BuildDownloadUpdatesForRetryImpl(

[rlarocque, 2014/01/08 20:30:08]

The reason we have separate Impl methods is to allow us to test the building of
request messages.  You should probably add a test to download_unittest.cc as you
add this function, and maybe update a few of the existing tests too.  (eg. Test
that the is_retry flag is set properly.)

Also, nit: please separate these two functions with a newline and add a comment
to the second one.

[haitaol1, 2014/01/10 00:15:58]

Done.

+    ModelTypeSet proto_request_types,
+    UpdateHandlerMap* update_handler_map,
+    sync_pb::GetUpdatesMessage* get_updates);
+
 // Sends the specified message to the server and stores the response in a member
 // of the |session|'s StatusController.
 SYNC_EXPORT_PRIVATE SyncerError