Revert of ui: Move ui_unittests.gyp into ui/base.

Revert of ui: Move ui_unittests.gyp into ui/base. (patchset #5 id:80001 of https://codereview.chromium.org/506483002/)

Reason for revert:
it breaks clobber build of ios_dbg_simulator.

Original issue's description:
> ui: Move ui_unittests.gyp into ui/base.
> 
> ui_unittests.gyp -> ui_base_tests.gyp (follow gfx_tests.gyp pattern).
> ui_unittests_bundle.gypi -> ui/base/ui_base_tests_bundle.gypi
> ui_unittests.isolate -> ui_base_tests.isolate
> 
> Add a TODO assigned to me to rename ui_unittests target to
> ui_base_unittests when buildbot is updated.
> 
> BUG=331829, 373148, 299841, 103304
> TEST=ui_unittests
> R=sky@chromium.org
> 
> Committed: https://chromium.googlesource.com/chromium/src/+/60f6892f7223f9d6db92314edb5df9b63d25720f

TBR=sky@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=331829, 373148, 299841, 103304
Committed: https://crrev.com/6297a2f1e441c46d6f8ca37a3798fe6fbdd6cc4c
Cr-Commit-Position: refs/heads/master@{#292657}

[tfarina, 2014-08-29 17:00:36]

Created Revert of ui: Move ui_unittests.gyp into ui/base.

[commit-bot: I haz the power, 2014-08-29 17:01:27]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tfarina@chromium.org/522843002/1

[commit-bot: I haz the power, 2014-08-29 17:02:11]

Committed patchset #1 (id:1) as 8aab73d59736274f3a52f5a92248af919dd0ff5a

[commit-bot: I haz the power, 2014-09-10 03:09:27]

Patchset 1 (id:??) landed as
https://crrev.com/6297a2f1e441c46d6f8ca37a3798fe6fbdd6cc4c
Cr-Commit-Position: refs/heads/master@{#292657}