Revert of Fix breaking change in It2me Host on Ozone

Revert of Fix breaking change in It2me Host on Ozone (patchset #2 id:20001 of https://codereview.chromium.org/931393003/)

Reason for revert:
does not compile

Original issue's description:
> Fix breaking change in It2me Host on Ozone
>
> Due to a recent threading changes, the Ozone SystemInputInjector must be
> created on the UI thread.
>
> This CL moves the creation of the input injector and input controller on
> to the browser UI thread.
>
> BUG=458314
>
> Committed: https://crrev.com/9c59eedd7720845a5bc93b6dbc72639305c52ea7
> Cr-Commit-Position: refs/heads/master@{#316883}

TBR=sergeyu@chromium.org,kelvinp@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=458314
Committed: https://crrev.com/ffbcf31d4bd3c3054a874e8333dd835839281266
Cr-Commit-Position: refs/heads/master@{#316898}

[spang, 2015-02-18 21:43:16]

Created Revert of Fix breaking change in It2me Host on Ozone

[commit-bot: I haz the power, 2015-02-18 21:43:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/932233002/1

[commit-bot: I haz the power, 2015-02-18 21:44:35]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-18 21:45:05]

Patchset 1 (id:??) landed as
https://crrev.com/ffbcf31d4bd3c3054a874e8333dd835839281266
Cr-Commit-Position: refs/heads/master@{#316898}