Connect to QProcess::finished to detect the exit status. In case the
process has crashed, signal the indexer.
On a crash, restart the process and feed it a smaller batch. If the
crashing batch contains only a single file, mark the file as failed, i.e.
add it to the "failedid" db and remove it from the content indexing db
to avoid further indexing attempts.
CCBUG: 375131