Instrumented libraries: fix zlib1g build on Precise.

BUG=435109
TBR=glider@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/744863003

Cr-Original-Commit-Position: refs/heads/master@{#305036}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 7b445146f03bb7886c66662513fef0b21f49a06c
1 file changed