Remove some friend declarations in ThreadRestrictions that are no more needed.

Remove some friend declarations in ThreadRestrictions that are no more needed.

The associated bugs look addressed. In some cases, even the mentioned
classes themselves are not present any more.

BUG=none
TEST=it compiles.

Committed: https://crrev.com/823a646501c4d8c28719ec25ea80cafc047f40d7
Cr-Commit-Position: refs/heads/master@{#300039}

[kinaba, 2014-10-16 05:27:41]

kinaba@chromium.org changed reviewers:
+ jam@chromium.org

[kinaba, 2014-10-16 05:27:41]

PTAL.

[jam, 2014-10-16 16:52:36]

On 2014/10/16 05:27:41, kinaba wrote:
> PTAL.

nice, lgtm

[kinaba, 2014-10-16 23:31:32]

The CQ bit was checked by kinaba@chromium.org

[commit-bot: I haz the power, 2014-10-16 23:33:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/653243004/1

[commit-bot: I haz the power, 2014-10-17 01:47:28]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-17 01:48:56]

Patchset 1 (id:??) landed as
https://crrev.com/823a646501c4d8c28719ec25ea80cafc047f40d7
Cr-Commit-Position: refs/heads/master@{#300039}