OP_ON_EXTERNAL_CACHE_HIT  136 net/disk_cache/blockfile/in_flight_backend_io.cc   operation_ = OP_ON_EXTERNAL_CACHE_HIT;
OP_ON_EXTERNAL_CACHE_HIT  262 net/disk_cache/blockfile/in_flight_backend_io.cc     case OP_ON_EXTERNAL_CACHE_HIT: