add a libjpeg test

add a libjpeg test

This tests for a bug in libjpeg where INT32 is typedefed to long
and memory is written to outside of the array.

BUG=skia:2791
Committed: https://skia.googlesource.com/skia/+/a0cc8334dab67746c6a74807db92ce2607ed52ff

[hal.canary, 2014-08-01 14:16:19]

used malloc, removed failing assert

[djsollen, 2014-08-01 14:21:26]

lgtm with a few nits

https://codereview.chromium.org/435753002/diff/20001/tests/ImageDecodingTest.cpp
File tests/ImageDecodingTest.cpp (right):

https://codereview.chromium.org/435753002/diff/20001/tests/ImageDecodingTest....
tests/ImageDecodingTest.cpp:761: // If the pixels in fPixles are big enough, use
them.
fPixels

https://codereview.chromium.org/435753002/diff/20001/tests/ImageDecodingTest....
tests/ImageDecodingTest.cpp:773: SingleAllocator(void* p, size_t s) :
fPixels(p), fSize(s) { }
put constructor/destructor at the top of class.

[hal.canary, 2014-08-01 14:59:35]

The CQ bit was checked by halcanary@google.com

[commit-bot: I haz the power, 2014-08-01 14:59:48]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/halcanary@google.com/435753002/40001

[commit-bot: I haz the power, 2014-08-01 15:12:48]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  Build-Win-VS2013-x86-Debug-Trybot on tryserver.skia
(http://108.170.220.76:10117/builders/Build-Win-VS2013-x86-Debug-Trybot/builds...)
  Test-Ubuntu13.10-ShuttleA-NoGPU-x86_64-Debug-Trybot on tryserver.skia
(http://108.170.220.120:10117/builders/Test-Ubuntu13.10-ShuttleA-NoGPU-x86_64-...)

[commit-bot: I haz the power, 2014-08-01 15:20:08]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-08-01 15:20:09]

Try jobs failed on following builders:
  Build-Win-VS2013-x86-Debug-Trybot on tryserver.skia
(http://108.170.220.76:10117/builders/Build-Win-VS2013-x86-Debug-Trybot/builds...)

[hal.canary, 2014-08-01 17:17:50]

The CQ bit was checked by halcanary@google.com

[commit-bot: I haz the power, 2014-08-01 17:18:50]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/halcanary@google.com/435753002/40001

[commit-bot: I haz the power, 2014-08-01 17:31:52]

Change committed as a0cc8334dab67746c6a74807db92ce2607ed52ff