[Ozone] Initialize the message filter from the dummy channel

[Ozone] Initialize the message filter from the dummy channel

Anything relying on the filter being added would not be initialized
otherwise.

BUG=none
NOTRY=true

Committed: https://crrev.com/fdc143bb7d15f65d41a1d531fb3190ee02700d8e
Cr-Commit-Position: refs/heads/master@{#312901}

[dnicoara, 2015-01-22 23:07:51]

dnicoara@chromium.org changed reviewers:
+ alexst@chromium.org

[dnicoara, 2015-01-22 23:07:51]

This is important if we're running ozone_demo with GBM surfaceless otherwise the
helper thread would never be initialized.

[alexst (slow to review), 2015-01-23 18:29:20]

lgtm

[dnicoara, 2015-01-23 19:42:31]

The CQ bit was checked by dnicoara@chromium.org

[commit-bot: I haz the power, 2015-01-23 19:43:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/872473002/1

[commit-bot: I haz the power, 2015-01-23 19:45:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-23 19:46:29]

Patchset 1 (id:??) landed as
https://crrev.com/fdc143bb7d15f65d41a1d531fb3190ee02700d8e
Cr-Commit-Position: refs/heads/master@{#312901}