Instead of using Sha1 to hash the hostname, use plain text.

The guidance is to not use Sha1 for obfuscation. There is no
security concern for hostname since it is generally considered to
be public info.

Change-Id: If587d9e9480606ec9df0b164313026ed49a4a4ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2351453
Commit-Queue: Joe Downing <joedow@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797580}