[Sync] Don't commit items with predecessors/parents in conflict.

chrome/browser/sync/engine/process_commit_response_command.cc

Index: chrome/browser/sync/engine/process_commit_response_command.cc
diff --git a/chrome/browser/sync/engine/process_commit_response_command.cc b/chrome/browser/sync/engine/process_commit_response_command.cc
index 995e49ea33dc30fc134597608b5a1ab4177da003..35ec4f874ea8701c6e3821affde5648b761ec297 100644
--- a/chrome/browser/sync/engine/process_commit_response_command.cc
+++ b/chrome/browser/sync/engine/process_commit_response_command.cc
@@ -461,6 +461,12 @@ void ProcessCommitResponseCommand::OverrideClientFieldsAfterCommit(
     DCHECK_EQ(entry_response.position_in_parent(),
         local_entry->Get(SERVER_POSITION_IN_PARENT));
 
+    DVLOG(1) << "Response overrides local position of "
+             << local_entry->Get(syncable::ID).GetServerId()
+             << " from "
+             << local_entry->Get(syncable::SERVER_POSITION_IN_PARENT)
+             << " to " << entry_response.position_in_parent();
+
     // We just committed successfully, so we assume that the position
     // value we got applies to the PARENT_ID we submitted.
     syncable::Id new_prev = local_entry->ComputePrevIdFromServerPosition(