Mojo: Fixes to current virtual/override style in mojo/edk/.

Mojo: Fixes to current virtual/override style in mojo/edk/.

This was mostly done in https://codereview.chromium.org/668663006/, but:
* it missed things deriving from testing::Test for some reason;
* it didn't touch Windows-only files (for more obvious reasons).

R=sky@chromium.org
BUG=417463
Committed: https://chromium.googlesource.com/chromium/src/+/3a09fd48b0780995311f1cebc1b87c3648dc0552

[sky, 2014-10-21 16:00:32]

LGTM

[viettrungluu, 2014-10-21 16:02:44]

The CQ bit was checked by viettrungluu@chromium.org

[commit-bot: I haz the power, 2014-10-21 16:03:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/670743002/1

[commit-bot: I haz the power, 2014-10-21 16:54:46]

Patchset 1 (id:??) landed as
https://crrev.com/3a09fd48b0780995311f1cebc1b87c3648dc0552
Cr-Commit-Position: refs/heads/master@{#300502}

[viettrungluu, 2014-10-21 16:54:50]

Committed patchset #1 (id:1) manually as
3a09fd48b0780995311f1cebc1b87c3648dc0552 (presubmit successful).