Remove usage of FOR_EACH_OBSERVER macro in components/history

Remove usage of FOR_EACH_OBSERVER macro in components/history

Observer lists now support range-based for loops.

BUG=655021
Committed: https://crrev.com/720393e91b2cfe204d8ceee35c9b0b4dad69d2ce
Cr-Commit-Position: refs/heads/master@{#425848}

[Eric Willigers, 2016-10-16 23:44:18]

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

[commit-bot: I haz the power, 2016-10-16 23:44:26]

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

[Eric Willigers, 2016-10-17 00:50:35]

ericwilligers@chromium.org changed reviewers:
+ sky@chromium.org

[commit-bot: I haz the power, 2016-10-17 01:01:57]

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

[commit-bot: I haz the power, 2016-10-17 01:01:58]

Dry run: This issue passed the CQ dry run.

[sky, 2016-10-17 15:55:25]

Similar request about using type.

[Eric Willigers, 2016-10-17 23:39:26]

On 2016/10/17 15:55:25, sky wrote:
> Similar request about using type.

Done. PTAL.

[sky, 2016-10-17 23:50:29]

LGTM

[Eric Willigers, 2016-10-17 23:53:32]

The CQ bit was checked by ericwilligers@chromium.org

[commit-bot: I haz the power, 2016-10-17 23:54:12]

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, 2016-10-18 01:25:57]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-10-18 01:28:19]

Description was changed from

==========
Remove usage of FOR_EACH_OBSERVER macro in components/history

Observer lists now support range-based for loops.


BUG=655021
==========

to

==========
Remove usage of FOR_EACH_OBSERVER macro in components/history

Observer lists now support range-based for loops.

BUG=655021

Committed: https://crrev.com/720393e91b2cfe204d8ceee35c9b0b4dad69d2ce
Cr-Commit-Position: refs/heads/master@{#425848}
==========

[commit-bot: I haz the power, 2016-10-18 01:28:20]

Patchset 2 (id:??) landed as
https://crrev.com/720393e91b2cfe204d8ceee35c9b0b4dad69d2ce
Cr-Commit-Position: refs/heads/master@{#425848}