Mojo/Go build rule changes.

TBR=darin@chromium.org for trivial third_party/*/BUILD.gn changes

Review URL: https://codereview.chromium.org/698733002

Cr-Original-Commit-Position: refs/heads/master@{#302375}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 8c0287411314d7cbebc15608db1d48e356b79f92
1 file changed