Revert of Store the list of trial tokens in OriginTrialContext

Revert of Store the list of trial tokens in OriginTrialContext (patchset #6 id:140001 of https://codereview.chromium.org/1833063002/ )

Reason for revert:
Broke release component builds on Windows

Original issue's description:
> Store the list of trial tokens in OriginTrialContext
> 
> Refactor the way tokens are found by storing them separately from the
> document tree in OriginTrialContext.
> 
> This simplifies the architecture a bit, making it easier to:
> - add support for tokens specified in http headers.
> - add support for trials in workers.
> - somehow limit which tokens are considered "valid".
> 
> BUG=601108
> 
> Committed: https://crrev.com/b03579678fa2678748d5cbcec2e18a8a08e40701
> Cr-Commit-Position: refs/heads/master@{#385504}

TBR=iclelland@chromium.org,rbyers@chromium.org,mek@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=601108

[Nico, 2016-04-08 01:49:28]

Created Revert of Store the list of trial tokens in OriginTrialContext

[commit-bot: I haz the power, 2016-04-08 01:49:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1875593003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1875593003/1

[commit-bot: I haz the power, 2016-04-08 02:01:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1875593003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1875593003/1

[commit-bot: I haz the power, 2016-04-08 02:32:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1875593003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1875593003/1

[commit-bot: I haz the power, 2016-04-08 03:02:21]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1875593003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1875593003/1

[commit-bot: I haz the power, 2016-04-08 03:19:53]

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

[commit-bot: I haz the power, 2016-04-08 03:19:54]

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

[hans, 2016-04-08 04:43:56]

The CQ bit was checked by hans@chromium.org

[commit-bot: I haz the power, 2016-04-08 04:44:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1875593003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1875593003/1

[commit-bot: I haz the power, 2016-04-08 04:50:28]

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

[commit-bot: I haz the power, 2016-04-08 04:50:30]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)
  linux_chromium_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[iclelland, 2016-04-08 13:34:51]

On 2016/04/08 04:50:30, commit-bot: I haz the power wrote:
> Try jobs failed on following builders:
>   chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
>
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)
>   linux_chromium_rel_ng on tryserver.chromium.linux (JOB_FAILED,
>
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

Looks like an ASSERT got changed to a DCHECK in Document.h in the meantime, so
the patch is failing. thakis@ - Is the original patch still in need of a revert?
(I don't see windows build failures in the waterfall, but I don't see an
explicit component buildbot either)

[hans, 2016-04-08 15:37:11]

On 2016/04/08 13:34:51, iclelland wrote:
> On 2016/04/08 04:50:30, commit-bot: I haz the power wrote:
> > Try jobs failed on following builders:
> >   chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
> >
>
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)
> >   linux_chromium_rel_ng on tryserver.chromium.linux (JOB_FAILED,
> >
>
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
> 
> Looks like an ASSERT got changed to a DCHECK in Document.h in the meantime, so
> the patch is failing. thakis@ - Is the original patch still in need of a
revert?
> (I don't see windows build failures in the waterfall, but I don't see an
> explicit component buildbot either)

shinyak fixed in https://codereview.chromium.org/1863323004