fix errors reported by the closure compiler.
fix errors reported by the closure compiler.

BUG=
TEST=https://docs.google.com/document/d/1Q8ClzNzg5TEi5AM2iwABfWOSGfapuW9POeeyN67WmcE/edit#heading=h.mtbm6h5nteci

Committed: https://crrev.com/e62ea13559af44e550c1ba7cad9e704ecba96eb4
Cr-Commit-Position: refs/heads/master@{#369709}

Review URL: https://codereview.chromium.org/1589283002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#370305}

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