Propagate decorators properly in telemetry_perf_unittests.

Propagate decorators properly in telemetry_perf_unittests.

The load_tests() protocol we use for running the
benchmark_smoke_unittests in telemetry_perf_unittests does some
complicated python hacking in order to synthesize python unit
test cases from the benchmark files.

Prior to the fix in this patch, any decorators that were applied
to the original benchmarks (in order to enable or disable tests)
were being ignored. This patch makes sure the decorated
enabled/disabled strings are copied over to the synthesized test
method.

R=tonyg@chromium.org, dtu@chromium.org
BUG=

Committed: https://crrev.com/50a0abfb13b02bb65ebb23ab8a208499db0c795d
Cr-Commit-Position: refs/heads/master@{#301991}

[tonyg, 2014-10-29 19:58:42]

lgtm % adding a TODO about trying to find the next test in the case that one is
disabled

[Dirk Pranke, 2014-10-29 22:27:19]

The CQ bit was checked by dpranke@chromium.org

[commit-bot: I haz the power, 2014-10-29 22:29:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/687893002/20001

[commit-bot: I haz the power, 2014-10-30 00:35:11]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-10-30 00:36:17]

Patchset 2 (id:??) landed as
https://crrev.com/50a0abfb13b02bb65ebb23ab8a208499db0c795d
Cr-Commit-Position: refs/heads/master@{#301991}