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Also fix code links in documentation.

TBR=crouleau@chromium.org,tdresser@chromium.org

Change-Id: Id9be6d9342d29d34a4d5c4aaa399915e5e7c3516
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1587838Reviewed-by: Annie Sullivan <sullivan@chromium.org>
Commit-Queue: Annie Sullivan <sullivan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#654830}