arc: Use FOR_EACH_OBSERVER in InstanceHolder

arc: Use FOR_EACH_OBSERVER in InstanceHolder

Now that FOR_EACH_OBSERVER supports dependent types, we can use it
instead of its expansion.

BUG=627209
TEST=trybots

Committed: https://crrev.com/05b7d4f124a608289ff685341c146cb7e38f1fd6
Cr-Commit-Position: refs/heads/master@{#405174}

[Luis Héctor Chávez, 2016-07-13 14:48:34]

The CQ bit was checked by lhchavez@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-07-13 14:48:47]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Luis Héctor Chávez, 2016-07-13 14:58:39]

lhchavez@chromium.org changed reviewers:
+ hidehiko@chromium.org

[Luis Héctor Chávez, 2016-07-13 14:58:39]

PTAL

[commit-bot: I haz the power, 2016-07-13 15:20:24]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-13 15:20:25]

Dry run: This issue passed the CQ dry run.

[hidehiko, 2016-07-13 16:04:38]

lgtm

[Luis Héctor Chávez, 2016-07-13 16:07:42]

The CQ bit was checked by lhchavez@chromium.org

[commit-bot: I haz the power, 2016-07-13 16:07:59]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-13 16:14:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-07-13 16:15:08]

CQ bit was unchecked.

[commit-bot: I haz the power, 2016-07-13 16:16:24]

Description was changed from

==========
arc: Use FOR_EACH_OBSERVER in InstanceHolder

Now that FOR_EACH_OBSERVER supports dependent types, we can use it
instead of its expansion.

BUG=627209
TEST=trybots
==========

to

==========
arc: Use FOR_EACH_OBSERVER in InstanceHolder

Now that FOR_EACH_OBSERVER supports dependent types, we can use it
instead of its expansion.

BUG=627209
TEST=trybots

Committed: https://crrev.com/05b7d4f124a608289ff685341c146cb7e38f1fd6
Cr-Commit-Position: refs/heads/master@{#405174}
==========

[commit-bot: I haz the power, 2016-07-13 16:16:25]

Patchset 1 (id:??) landed as
https://crrev.com/05b7d4f124a608289ff685341c146cb7e38f1fd6
Cr-Commit-Position: refs/heads/master@{#405174}