Don't declare displayCache variable if PROGRAM_CACHE_STATS not defined.

BUG=
R=robertphillips@google.com

Review URL: https://codereview.chromium.org/23757053

git-svn-id: http://skia.googlecode.com/svn/trunk@11301 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed