Fix captive portal compile issues for android.

Fix captive portal compile issues for android.

Caused by:
https://codereview.chromium.org/1365733005

TBR=felt@chromium.org
NOTRY=true
BUG=488673
Committed: https://crrev.com/bf696bf90db4d3fe24de8dae51be3b029b4b46b7
Cr-Commit-Position: refs/heads/master@{#351391}

[Ted C, 2015-09-29 20:36:17]

tedchoc@chromium.org changed reviewers:
+ felt@chromium.org, yusufo@chromium.org

[Ted C, 2015-09-29 20:36:21]

The CQ bit was checked by tedchoc@chromium.org

[commit-bot: I haz the power, 2015-09-29 20:37:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1377943004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1377943004/1

[Ted C, 2015-09-29 20:38:04]

On 2015/09/29 20:37:33, commit-bot: I haz the power wrote:
> CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/1377943004/1
> View timeline at
>  https://chromium-cq-status.appspot.com/patch-timeline/1377943004/1

This was fixes for the following errors:
../../chrome/browser/ssl/captive_portal_metrics_recorder.h:45:8: error: private
field 'captive_portal_detection_enabled_' is not used
[-Werror,-Wunused-private-field]
  bool captive_portal_detection_enabled_;
       ^
../../chrome/browser/ssl/captive_portal_metrics_recorder.h:47:8: error: private
field 'captive_portal_probe_completed_' is not used
[-Werror,-Wunused-private-field]
  bool captive_portal_probe_completed_;
       ^
../../chrome/browser/ssl/captive_portal_metrics_recorder.h:49:8: error: private
field 'captive_portal_no_response_' is not used [-Werror,-Wunused-private-field]
  bool captive_portal_no_response_;
       ^
../../chrome/browser/ssl/captive_portal_metrics_recorder.h:50:8: error: private
field 'captive_portal_detected_' is not used [-Werror,-Wunused-private-field]
  bool captive_portal_detected_;

[commit-bot: I haz the power, 2015-09-29 20:44:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-29 20:45:19]

Patchset 1 (id:??) landed as
https://crrev.com/bf696bf90db4d3fe24de8dae51be3b029b4b46b7
Cr-Commit-Position: refs/heads/master@{#351391}