[perf] Safer operations when using sql.
[perf] Safer operations when using sql.

Scan() calls Close() so chain them to QueryRow.
Scan is also able to handle a nil row so this is safe.

Bug: skia:
Change-Id: I398ac3cf25cf0341b9a8a57de1c3c624caaf6549
Reviewed-on: https://skia-review.googlesource.com/38723
Reviewed-by: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>
Commit-Queue: Joe Gregorio <b9cf2471ff6d33504cafe8e6f356b732b2cadced@google.com>

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