favor DCHECK_CURRENTLY_ON for better logs in chrome/browser/prerender/, prefetch and printing

favor DCHECK_CURRENTLY_ON for better logs in chrome/browser/prerender/, prefetch and printing module

BUG=466848
TBR=gavinp@chromium.org

Committed: https://crrev.com/bcce43beb91324aebed2f5bc5ccad231406a1ca9
Cr-Commit-Position: refs/heads/master@{#327657}

[anujsharma, 2015-04-27 10:47:02]

anujk.sharma@samsung.com changed reviewers:
+ gavinp@chromium.org, vitalybuka@chromium.org

[anujsharma, 2015-04-27 10:47:03]

vitalybuka@chromium.org: Please review changes in chrome/browser/printing

gavinp@chromium.org: Please review changes in chrome/browser/prerender/ and
prefetch

[Vitaly Buka (NO REVIEWS), 2015-04-27 18:07:02]

lgtm

[anujsharma, 2015-04-29 12:09:57]

@Gavnip 

Could you please give a thumbs up for this CL.

Thanks!!

[davidben, 2015-04-29 15:38:34]

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

[davidben, 2015-04-29 15:38:35]

prerender lgtm

[anujsharma, 2015-04-30 05:03:55]

Since it is very trivial change, adding gavnip as TBR.

Trying to land.

[anujsharma, 2015-04-30 05:03:59]

The CQ bit was checked by anujk.sharma@samsung.com

[commit-bot: I haz the power, 2015-04-30 05:04:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1104043002/20001

[commit-bot: I haz the power, 2015-04-30 06:37:29]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-04-30 06:38:21]

Patchset 2 (id:??) landed as
https://crrev.com/bcce43beb91324aebed2f5bc5ccad231406a1ca9
Cr-Commit-Position: refs/heads/master@{#327657}