Add missing stdlib include for sample
Add missing stdlib include for sample

BUG=none
R=machenbach@chromium.org, machenbach@chromium.or
LOG=n

Review URL: https://codereview.chromium.org/1113563002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#28108}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh