Revert of Fix Flaky EncryptedMediaTest

Revert of Fix Flaky EncryptedMediaTest (patchset #1 id:1 of https://codereview.chromium.org/823743002/)

Reason for revert:
This changes introduces a new problem that is breaking the builds (e.g. http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20MSan%20Browser%20%281%29/builds/3905).

Original issue's description:
> Fix Flaky EncryptedMediaTest
>
> Tests are flaky as setMediaKeys() was not completing before the
> "encrypted" event was generated. Change delays setting the video
> source until setMediaKeys() completes.
>
> BUG=444683
> TEST=Failing tests run fine locally
>
> Committed: https://crrev.com/37edfbac393c04549884ec15ce612a376a5be6ff
> Cr-Commit-Position: refs/heads/master@{#309568}

TBR=xhwang@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=444683
Committed: https://crrev.com/95b0f9c82b73a5826fdd509ab4c6e7b1663bd2aa
Cr-Commit-Position: refs/heads/master@{#309587}

[jrummell, 2014-12-23 22:51:00]

Created Revert of Fix Flaky EncryptedMediaTest

[commit-bot: I haz the power, 2014-12-23 22:51:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/826603002/1

[xhwang, 2014-12-23 22:51:55]

lgtm

[commit-bot: I haz the power, 2014-12-23 22:52:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-12-23 22:53:35]

Patchset 1 (id:??) landed as
https://crrev.com/95b0f9c82b73a5826fdd509ab4c6e7b1663bd2aa
Cr-Commit-Position: refs/heads/master@{#309587}