Remove dead code from libwebp image decoder

R=scroggo@google.com, markkilgard@gmail.com

Author: bsalomon@google.com

Review URL: https://chromiumcodereview.appspot.com/23480043

git-svn-id: http://skia.googlecode.com/svn/trunk@11141 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed