message: [lldb] Small optimization of FormatMap::Delete
diff: @@ -89,7 +89,7 @@ public:
  MapIterator iter = m_map.find(name);
  if (iter == m_map.end())
  return false;
  - m_map.erase(name);
  + m_map.erase(iter);
  if (listener)
  listener->Changed();
  return true;
  