Correct addition of scheib, move from content/shell/OWNERS to ./browser/layout_test/OWNERS

Correct addition of scheib, move from content/shell/OWNERS to ./browser/layout_test/OWNERS

This enables ownership of content shell support for testing
Web Bluetooth. An example of early support being added in
https://codereview.chromium.org/1132943002
content/shell/browser/layout_test/layout_test_bluetooth_adapter_provider.h/cc

This change corrects https://codereview.chromium.org/1142523003
which incorrectly used the per-file directive. per-file only applies
to files in the same directory as the OWNERS file.

BUG=420275
Committed: https://crrev.com/97d5002e1966dfef3c630ae8759ea9d12b7cbfea
Cr-Commit-Position: refs/heads/master@{#329975}

[scheib, 2015-05-14 23:20:22]

scheib@chromium.org changed reviewers:
+ jochen@chromium.org

[jochen (gone - plz use gerrit), 2015-05-14 23:29:12]

lgtm

[scheib, 2015-05-14 23:30:51]

The CQ bit was checked by scheib@chromium.org

[commit-bot: I haz the power, 2015-05-14 23:31:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1128423004/1

[commit-bot: I haz the power, 2015-05-14 23:39:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-14 23:40:53]

Patchset 1 (id:??) landed as
https://crrev.com/97d5002e1966dfef3c630ae8759ea9d12b7cbfea
Cr-Commit-Position: refs/heads/master@{#329975}