Remove stale includes, mark histogram as obsolete.

Remove stale includes, mark histogram as obsolete.

This CL removes some stale includes missed by
https://codereview.chromium.org/1295323002/ and marks the
histogram Settings.ZoomLevelPreferencesMigrated as 'obsolete'.

TBR=thestig@chromium.org

BUG=420643
Committed: https://crrev.com/15b71416d97d588865d27daefa5f97541c45cf2f
Cr-Commit-Position: refs/heads/master@{#344775}

[wjmaclean, 2015-08-19 13:52:55]

wjmaclean@chromium.org changed reviewers:
+ gab@chromium.org

[wjmaclean, 2015-08-19 13:52:56]

Addressing issues from comments on https://codereview.chromium.org/1295323002/,
please take a look.

[gab, 2015-08-19 19:35:08]

lgtm, thanks

https://codereview.chromium.org/1297503008/diff/1/tools/metrics/histograms/hi...
File tools/metrics/histograms/histograms.xml (right):

https://codereview.chromium.org/1297503008/diff/1/tools/metrics/histograms/hi...
tools/metrics/histograms/histograms.xml:40104: +    of users have had their zoom
level prefs migrated.
Up to histograms OWNERS but I don't think there is much precedent for having a
detailed explanation as to why, "Deprecated 2015-08-18" is good enough IMO, git
blame can come to the rescue if more context is required.

[wjmaclean, 2015-08-19 19:53:36]

wjmaclean@chromium.org changed reviewers:
+ mpearson@chromium.org, thestig@chromium.org

[wjmaclean, 2015-08-19 19:53:36]

mpearson@chromium.org: Please review changes in histograms.xml

[wjmaclean, 2015-08-19 19:54:14]

wjmaclean@chromium.org changed reviewers:
- mpearson@chromium.org, thestig@chromium.org

[wjmaclean, 2015-08-19 19:54:49]

wjmaclean@chromium.org changed reviewers:
+ rkaplow@chromium.org

[wjmaclean, 2015-08-19 19:54:49]

rkaplow@chromium.org: Please review changes in histograms.xml

[Lei Zhang, 2015-08-19 21:06:04]

thestig@chromium.org changed reviewers:
+ thestig@chromium.org

[Lei Zhang, 2015-08-19 21:06:04]

lgtm

[wjmaclean, 2015-08-20 12:14:00]

wjmaclean@chromium.org changed reviewers:
- rkaplow@chromium.org

[wjmaclean, 2015-08-20 12:15:01]

wjmaclean@chromium.org changed reviewers:
+ jwd@chromium.org

[wjmaclean, 2015-08-20 12:15:01]

jwd@chromium.org: Please review changes in histograms.xml

[jwd, 2015-08-20 18:46:49]

lgtm

[wjmaclean, 2015-08-20 18:53:07]

The CQ bit was checked by wjmaclean@chromium.org

[wjmaclean, 2015-08-20 18:53:08]

The patchset sent to the CQ was uploaded after l-g-t-m from gab@chromium.org
Link to the patchset: https://codereview.chromium.org/1297503008/#ps20001
(title: "Simplify obsolescence comment.")

[commit-bot: I haz the power, 2015-08-20 18:53:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1297503008/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1297503008/20001

[commit-bot: I haz the power, 2015-08-20 21:56:23]

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

[commit-bot: I haz the power, 2015-08-20 21:56:24]

Try jobs failed on following builders:
  linux_android_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_android_r...)

[wjmaclean, 2015-08-21 13:20:44]

The CQ bit was checked by wjmaclean@chromium.org

[commit-bot: I haz the power, 2015-08-21 13:22:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1297503008/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1297503008/20001

[commit-bot: I haz the power, 2015-08-21 15:42:00]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-08-21 15:42:39]

Patchset 2 (id:??) landed as
https://crrev.com/15b71416d97d588865d27daefa5f97541c45cf2f
Cr-Commit-Position: refs/heads/master@{#344775}