athena: Avoid initializaing chromeos::Network for tests.

athena: Avoid initializaing chromeos::Network for tests.

Initializaing chromeos::Network triggers a whole bunch of things that are
not necessary or useful in tests. So avoid initializing this subsystem, since
none of the tests depend on it. Tests that do depend on this in the future
should explicitly initialize this from SetUp().

This change brings down the runtime of athena_unittests significantly.

BUG=412535
R=oshima@chromium.org

Committed: https://crrev.com/9ac6e8a2e435f3e732996c57840fb109b5cc4f6e
Cr-Commit-Position: refs/heads/master@{#300491}

[sadrul, 2014-10-20 21:52:52]

sadrul@chromium.org changed reviewers:
+ oshima@chromium.org

[oshima, 2014-10-21 00:15:07]

lgtm

[commit-bot: I haz the power, 2014-10-21 15:44:11]

Patchset 1 (id:??) landed as
https://crrev.com/9ac6e8a2e435f3e732996c57840fb109b5cc4f6e
Cr-Commit-Position: refs/heads/master@{#300491}

[sadrul, 2014-10-21 15:44:11]

Committed patchset #1 (id:1) manually as
9ac6e8a2e435f3e732996c57840fb109b5cc4f6e (presubmit successful).