[Telemetry] Fix NotImplementedError exceptions.

Raise NotImplementedError exceptions correctly.

BUG=439346
Committed: https://crrev.com/e7cb2a354e20a4bb0aa1e427348e85e2486c9288
Cr-Commit-Position: refs/heads/master@{#307055}

[slamm, 2014-12-05 17:47:18]

slamm@chromium.org changed reviewers:
+ chrishenry@google.com, nednguyen@google.com

[slamm, 2014-12-05 17:47:19]

Chris suggested breaking this out from
https://codereview.chromium.org/776883004/.

[chrishenry, 2014-12-05 17:50:16]

The CQ bit was checked by chrishenry@google.com

[chrishenry, 2014-12-05 17:50:16]

lgtm

[commit-bot: I haz the power, 2014-12-05 17:51:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/761863007/1

[commit-bot: I haz the power, 2014-12-05 17:57:07]

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

[commit-bot: I haz the power, 2014-12-05 17:57:08]

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

[chrishenry, 2014-12-05 18:03:55]

Well, that's a bummer, can you also fix the lint failure (add empty methods to
AndroidAppBackend)?

https://codereview.chromium.org/761863007/diff/1/tools/telemetry/telemetry/co...
File tools/telemetry/telemetry/core/backends/app_backend.py (right):

https://codereview.chromium.org/761863007/diff/1/tools/telemetry/telemetry/co...
tools/telemetry/telemetry/core/backends/app_backend.py:34: raise
NotImplementedError
Can you move this next the the other @property?

[slamm, 2014-12-05 18:17:50]

Lint and reorder

[slamm, 2014-12-05 18:18:25]

The CQ bit was checked by slamm@chromium.org

[commit-bot: I haz the power, 2014-12-05 18:18:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/761863007/20001

[commit-bot: I haz the power, 2014-12-05 19:18:23]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-12-05 19:19:14]

Patchset 2 (id:??) landed as
https://crrev.com/e7cb2a354e20a4bb0aa1e427348e85e2486c9288
Cr-Commit-Position: refs/heads/master@{#307055}