[Telemetry] Allow telemetry to run without adb root.

[Telemetry] Allow telemetry to run without adb root.

Without root the user must manually enable devtools debugging in settings. This
limitation is acceptable as we are able to detect it and instruct the user.

BUG=154415
TEST=Run a telemetry test on a production android image

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=175353

[tonyg, 2013-01-04 22:53:06]

ptal

I can't believe it was this easy

[nduca, 2013-01-05 01:17:15]

this looks awesome. I think we may need to resolve the kill problem though.

[tonyg, 2013-01-05 01:39:52]

On 2013/01/05 01:17:15, nduca wrote:
> this looks awesome. I think we may need to resolve the kill problem though.

Fixed.

[nduca, 2013-01-05 02:03:23]

the hills are alive with the sound of lgtmmmmmmmnesss.

[commit-bot: I haz the power, 2013-01-05 20:32:30]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/tonyg@chromium.org/11784007/4001

[commit-bot: I haz the power, 2013-01-05 20:46:38]

Retried try job too often on ios_dbg_simulator for step(s) sync_unit_tests,
unit_tests

[commit-bot: I haz the power, 2013-01-07 16:55:06]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/tonyg@chromium.org/11784007/4001