Re-enable ChannelMojo

Re-enable ChannelMojo

It was disabled due to crbug.com/466814 that is now fixed.
It's time to turn it on again.

R=viettrungluu@chromium.org
BUG=466814, 377980
Committed: https://crrev.com/c99c93842fa50f85888d069f0be962462f92a643
Cr-Commit-Position: refs/heads/master@{#322092}

Committed: https://crrev.com/ce41e7007dea7b653a7ee848419b47e582f165d2
Cr-Commit-Position: refs/heads/master@{#322886}

[Hajime Morrita, 2015-03-20 21:07:16]

This depends on https://codereview.chromium.org/1023043002/

[Hajime Morrita, 2015-03-24 21:21:04]

On 2015/03/20 21:07:16, morrita wrote:
> This depends on https://codereview.chromium.org/1023043002/

Trung: Rubberstamp please?

[viettrungluu, 2015-03-24 22:06:29]

lgtm

[Hajime Morrita, 2015-03-24 22:24:49]

Thanks!

[Hajime Morrita, 2015-03-24 22:24:52]

The CQ bit was checked by morrita@chromium.org

[commit-bot: I haz the power, 2015-03-24 22:26:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1021393002/1

[commit-bot: I haz the power, 2015-03-24 23:46:54]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-24 23:47:33]

Patchset 1 (id:??) landed as
https://crrev.com/c99c93842fa50f85888d069f0be962462f92a643
Cr-Commit-Position: refs/heads/master@{#322092}

[tkent, 2015-03-25 04:39:17]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1029263008/ by tkent@chromium.org.

The reason for reverting is: speculative revert for "Too many open files" on
various Mac bots.
e.g.
http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Mac10.9/builds/...
.

[Hajime Morrita, 2015-03-25 17:17:34]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1034753002/ by morrita@chromium.org.

The reason for reverting is: This depends on
https://codereview.chromium.org/1023043002, which was reverted..

[Hajime Morrita, 2015-03-30 20:25:55]

The CQ bit was checked by morrita@chromium.org

[Hajime Morrita, 2015-03-30 20:26:19]

Relanding as https://codereview.chromium.org/1040163002/ is in.

[commit-bot: I haz the power, 2015-03-30 20:26:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1021393002/1

[commit-bot: I haz the power, 2015-03-30 21:53:48]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-30 21:54:26]

Patchset 1 (id:??) landed as
https://crrev.com/ce41e7007dea7b653a7ee848419b47e582f165d2
Cr-Commit-Position: refs/heads/master@{#322886}