I suspect that the non-deterministic order of changed variables in the
generated Label constructor calls is what causes non-deterministic
builds, since this is the only change I observed locally in the
generated .cc files.

Drive-by cleanup: follow style-guide by avoiding mutable ref parameter.

Bug: chromium:867308
Change-Id: I137af359df570ee11b95cb620ace179bf93481c5
Reviewed-on: https://chromium-review.googlesource.com/1148729Reviewed-by: Daniel Clifford <danno@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54687}