Fix #include guard in header after https://codereview.chromium.org/1321123002 .
Fix #include guard in header after https://codereview.chromium.org/1321123002 .

BUG=509811
TEST=none

Review URL: https://codereview.chromium.org/1340203002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#348986}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk