Revert of mojo: Create a basic clipboard.

Revert of mojo: Create a basic clipboard. (patchset #29 id:540001 of https://codereview.chromium.org/562483002/)

Reason for revert:
Breaking GN builders.

http://build.chromium.org/p/chromium.linux/buildstatus?builder=Android%20GN&number=10604

http://build.chromium.org/p/chromium.linux/builders/Linux%20GN/builds/12120/steps/gn/logs/stdio

Original issue's description:
> mojo: Create a basic clipboard.
>
> This creates a basic clipboard interface and uses it from
> html_viewer. This is a minimal implementation and does not actually
> interact with the system clipboard.
>
> BUG=411039
>
> Committed: https://crrev.com/757286d8a2c778fe4622890140c9b9d2afd21063
> Cr-Commit-Position: refs/heads/master@{#295143}

TBR=dcheng@chromium.org,darin@chromium.org,sky@chromium.org,erg@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=411039
Committed: https://crrev.com/ae48dc2800a7f37030952ddfee957513da558ab9
Cr-Commit-Position: refs/heads/master@{#295152}

[Ken Rockot(use gerrit already), 2014-09-16 21:53:26]

Created Revert of mojo: Create a basic clipboard.

[commit-bot: I haz the power, 2014-09-16 21:54:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/579503003/1

[commit-bot: I haz the power, 2014-09-16 21:55:27]

Committed patchset #1 (id:1) as b62baa85919c04d226b697f53cfa03b75eed2750

[commit-bot: I haz the power, 2014-09-16 21:55:58]

Patchset 1 (id:??) landed as
https://crrev.com/ae48dc2800a7f37030952ddfee957513da558ab9
Cr-Commit-Position: refs/heads/master@{#295152}