OnMessageSentCallback  172 google_apis/gcm/engine/mcs_client.cc     const OnMessageSentCallback& message_sent_callback,
OnMessageSentCallback  106 google_apis/gcm/engine/mcs_client.h                   const OnMessageSentCallback& message_sent_callback,
OnMessageSentCallback  205 google_apis/gcm/engine/mcs_client.h   OnMessageSentCallback message_sent_callback_;