Revert of Provide v8 dependency on tracing.

Revert of Provide v8 dependency on tracing. (patchset #2 id:20001 of https://codereview.chromium.org/2068073002/ )

Reason for revert:
Feature not needed.

Original issue's description:
> Provide v8 dependency on tracing.
> 
> Related to https://codereview.chromium.org/2061933002/. When
> that CL lands, the variable introduced by the present CL would provide
> the root for the path to the tracing includes, in the context of the
> chromium build.
> 
> BUG=
> 
> Committed: https://crrev.com/6d4418ff859750f445af6e4612a5665ae2f84837
> Cr-Commit-Position: refs/heads/master@{#400355}

TBR=fmeawad@chromium.org,dpranke@chromium.org,mtrofin@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=

[Michael Achenbach, 2016-06-21 06:46:13]

The CQ bit was checked by machenbach@chromium.org

[Michael Achenbach, 2016-06-21 06:46:14]

Created Revert of Provide v8 dependency on tracing.

[commit-bot: I haz the power, 2016-06-21 06:46:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2085883002/1

[commit-bot: I haz the power, 2016-06-21 06:53:14]

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

[commit-bot: I haz the power, 2016-06-21 06:53:16]

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...)

[Michael Achenbach, 2016-06-21 07:55:40]

I assume you reverted this already in a different CL?

[Mircea Trofin, 2016-06-21 13:23:13]

On 2016/06/21 07:55:40, Michael Achenbach wrote:
> I assume you reverted this already in a different CL?

Yes, https://codereview.chromium.org/2072133003/