Give two ClampBufferSize functions distinct names

In some jumbo build configurations, two ClampBufferSize functions
in services/network ended up in the same translation unit which
caused compilation errors.

Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: I6b7ea9c226b114a10d59fa9891e67f83537c5ec6
Reviewed-on: https://chromium-review.googlesource.com/1238219
Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#593215}
2 files changed