innobase/btr/btr0btr.c:
  Enclose btr_print_size() and btr_print_tree() in #ifdef UNIV_BTR_PRINT
  Add trx_t* parameter to btr_validate_tree() and btr_validate_level().
  btr_validate_level(): Call trx_is_interrupted() on each page.
innobase/ibuf/ibuf0ibuf.c:
  Add trx_t* parameter to btr_validate_tree().
innobase/include/btr0btr.h:
  Enclose btr_print_size() and btr_print_tree() in #ifdef UNIV_BTR_PRINT
  Add trx_t* parameter to btr_validate_tree().
innobase/include/trx0trx.h:
  Declare trx_is_interrupted().
innobase/row/row0mysql.c:
  row_scan_and_check_index(): Check trx_is_interrupted() every 1,000
  scanned rows.
  row_check_table_for_mysql(): Check trx_is_interrupted()
  for each index after btr_validate_tree().
sql/ha_innodb.cc:
  Define trx_is_interrupted().