sql/ha_innodb.cc:
  Remove innobase_flush_log_at_trx_commit
  (set srv_flush_log_at_trx_commit directly).
sql/ha_innodb.h:
  Remove innobase_flush_log_at_trx_commit.
  Declare srv_flush_log_at_trx_commit.
sql/mysqld.cc:
  Bypass the innobase_flush_log_at_trx_commit variable.
storage/innobase/include/srv0srv.h:
  Change the type of srv_flush_log_at_trx_commit.
storage/innobase/srv/srv0srv.c:
  Change the type of srv_flush_log_at_trx_commit.