Cleaning up some tests

This removes some unused code and simplifies some dependencies. I'm planning to pull the audio code out into its own component, and it'll be clearer if I do minimal refactoring along the way.

Committed: https://crrev.com/88444c0bae2e77ab555a81a727d5ffa49500adf2
Cr-Commit-Position: refs/heads/master@{#314733}

[Charlie, 2015-02-05 00:11:06]

ckehoe@chromium.org changed reviewers:
+ rkc@chromium.org

[rkc, 2015-02-05 00:18:46]

lgtm

[Charlie, 2015-02-05 01:27:41]

The CQ bit was checked by ckehoe@chromium.org

[commit-bot: I haz the power, 2015-02-05 01:28:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/901753002/20001

[commit-bot: I haz the power, 2015-02-05 01:55:34]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-02-05 01:55:34]

Try jobs failed on following builders:
  win_chromium_x64_rel_ng on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[Charlie, 2015-02-05 02:55:16]

New patchsets have been uploaded after l-g-t-m from rkc@chromium.org

[Charlie, 2015-02-05 02:55:43]

The CQ bit was checked by ckehoe@chromium.org

[commit-bot: I haz the power, 2015-02-05 02:56:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/901753002/40001

[commit-bot: I haz the power, 2015-02-05 03:27:29]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-02-05 03:28:20]

Patchset 3 (id:??) landed as
https://crrev.com/88444c0bae2e77ab555a81a727d5ffa49500adf2
Cr-Commit-Position: refs/heads/master@{#314733}