Fix call to _ProfileDir.

Fix call to _ProfileDir.

I think this is a fix to this CL: https://codereview.chromium.org/656383002/
One of the internal bots has the following error:
  PullProfile at tools/telemetry/telemetry/core/platform/android_platform_backend.py:455
    self._ProfileDir(package), output_profile_path)
AttributeError: 'AndroidPlatformBackend' object has no attribute '_ProfileDir'
There does not seem to be a _ProfileDir, but there is a _GetProfileDir.

BUG=417542
Committed: https://crrev.com/0a537a904b0cb14cca715c0588700bc0b52fc53e
Cr-Commit-Position: refs/heads/master@{#302169}

[navabi, 2014-10-30 21:01:44]

navabi@google.com changed reviewers:
+ dtu@chromium.org, nednguyen@google.com, slamm@chromium.org,
tonyg@chromium.org, wuhu@google.com

[dtu, 2014-10-30 21:05:44]

lgtm

[nednguyen, 2014-10-30 21:06:10]

The CQ bit was checked by nednguyen@google.com

[wuhu, 2014-10-30 21:06:52]

On 2014/10/30 21:01:45, navabi wrote:

LGTM

[commit-bot: I haz the power, 2014-10-30 21:07:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/664583009/1

[commit-bot: I haz the power, 2014-10-30 22:10:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-30 22:10:54]

Patchset 1 (id:??) landed as
https://crrev.com/0a537a904b0cb14cca715c0588700bc0b52fc53e
Cr-Commit-Position: refs/heads/master@{#302169}