Revert of [Telemetry] Pass test_runner environment in local args instead of a global variable

Revert of [Telemetry] Pass test_runner environment in local args instead of a global variable (patchset #9 id:160001 of https://codereview.chromium.org/942663002/)

Reason for revert:
crbug.com/462063

Original issue's description:
> [Telemetry] Pass test_runner environment in local args instead of a global variable
>
> Also adds more fields to environment to narrow the scope of
> benchmark and user story set discovery. This should avoid problems
> with adding Python files to unrelated directories, and hides PageTests
> from external Telemetry benchmark runners like run_gpu_tests.py and
> chrome_proxy's run_benchmark.
>
> R=dtu,nednguyen,sullivan,kbr@chromium.org,bolian
> BUG=460181
> TEST=tools/perf/run_benchmark; content/test/gpu/run_gpu_tests.py; tools/chrome_proxy/run_benchmark  # All return a full and correct test list.
>
> Committed: https://crrev.com/1da5f7f70ea6dc7dd0667ea78637802c76305f5a
> Cr-Commit-Position: refs/heads/master@{#318149}

TBR=bolian@chromium.org,dtu@chromium.org,kbr@chromium.org,nednguyen@google.com,sullivan@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=460181
Committed: https://crrev.com/f29d78349447bc24719a98a80f1d90ae1f431952
Cr-Commit-Position: refs/heads/master@{#318175}

[eakuefner, 2015-02-26 02:37:44]

Created Revert of [Telemetry] Pass test_runner environment in local args instead
of a global variable

[commit-bot: I haz the power, 2015-02-26 02:38:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/955183003/1

[commit-bot: I haz the power, 2015-02-26 02:38:32]

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

[commit-bot: I haz the power, 2015-02-26 02:38:32]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[sullivan, 2015-02-26 02:46:59]

lgtm

[eakuefner, 2015-02-26 02:50:27]

The CQ bit was checked by eakuefner@chromium.org

[commit-bot: I haz the power, 2015-02-26 02:50:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/955183003/1

[commit-bot: I haz the power, 2015-02-26 02:51:46]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-26 02:52:28]

Patchset 1 (id:??) landed as
https://crrev.com/f29d78349447bc24719a98a80f1d90ae1f431952
Cr-Commit-Position: refs/heads/master@{#318175}