Only use JDCT_IFAST if it's supported.

When encoding to JPEG, do not switch to JDCT_IFAST unless
DCT_IFAST_SUPPORTED is defined.

Review URL: https://codereview.chromium.org/14031013

git-svn-id: http://skia.googlecode.com/svn/trunk@8728 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed