Patch fix for "Add jpeg_skip_scanlines() API to libjpeg-turbo"

Patch fix for "Add jpeg_skip_scanlines() API to libjpeg-turbo"
https://codereview.chromium.org/1271803002/

"jpeg_skip_scanlines() API, a subset decoding optimization
aimed at Android, was submitted upstream r1582. Pull that
change, and sundry fixes, into the Chromium repo.

This new API is targetted at Android devices, not Chrome,
and should have no affect on JPEG decode behavior or perf
of Chrome.

Chrome uses suspending data source JPEG decoding, and the
new API does not support such sources. Adding support for
suspending data sources is a future TODO, should the need
arise (refer to skbug.com/4036)."

BUG=515694
BUG=468914
R=agable@chromium.org

Committed: https://chromium.googlesource.com/chromium/deps/libjpeg_turbo/+/631e2dd119d49794e3572b6ca3f16ee39d59f372

[msarett, 2015-08-11 16:21:46]

msarett@google.com changed reviewers:
+ msarett@google.com, noel@chromium.org

[msarett, 2015-08-11 16:21:46]

I missed a line when manually integrating the patch.  A
silly error in my test setup caused me to run my test suite
with the skip feature turned off (ugh!).  Now that I am
actually running my tests, I caught the mistake.

Apologies for the inconvenience and the original broken
patch.

Also, while I'm modifying this file, we may as well consider this:
I don't consider myself enough of an expert in huffman
decoding to vet this, but *if* we trust the commit
description, it seems like something to integrate.
https://github.com/libjpeg-turbo/libjpeg-turbo/commit/317129beca9a5a344ef0236...

[msarett, 2015-08-11 19:57:21]

msarett@google.com changed reviewers:
+ agable@chromium.org

[msarett, 2015-08-11 19:57:21]

Adding agable, looks like Noel is out of town.

[agable, 2015-08-11 20:03:13]

lgtm

[agable, 2015-08-11 20:03:21]

Committed patchset #1 (id:1) manually as
631e2dd119d49794e3572b6ca3f16ee39d59f372 (presubmit successful).

[Noel Gordon, 2015-08-12 00:39:22]

https://codereview.chromium.org/1291463002/diff/1/jdhuff.c
File jdhuff.c (right):

https://codereview.chromium.org/1291463002/diff/1/jdhuff.c#newcode663
jdhuff.c:663: JBLOCKROW block = MCU_data ? MCU_data[blkn] : NULL;
Confusing: this change was in the original submit, right?

https://codereview.chromium.org/1271803002/diff/1/jdhuff.c

Anyho, seems you have included the line now, LGTM.

[msarett, 2015-08-12 12:09:47]

Yes this was included in the patch that was upstreamed to libjpeg-turbo.  I just
made a mistake and missed it on the first patch.