Remove SigninManager.isNewProfileManagementEnabled().

Remove SigninManager.isNewProfileManagementEnabled().

This method is no longer used. All Android code assumes that new profile
management is enabled.

BUG=393335
R=aruslan@chromium.org

Committed: https://chromium.googlesource.com/chromium/src/+/5778babeb264211044c1ff1ef6d2e41f07e341b4

[newt (away), 2015-01-31 02:17:41]

newt@chromium.org changed reviewers:
+ aruslan@chromium.org

[newt (away), 2015-01-31 02:17:42]

PTAL

I meant to send this out a while ago and just forgot about it.

[aruslan, 2015-01-31 02:37:02]

lgtm thanks!

[newt (away), 2015-01-31 02:44:49]

The CQ bit was checked by newt@chromium.org

[commit-bot: I haz the power, 2015-01-31 02:46:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/890113002/1

[commit-bot: I haz the power, 2015-01-31 04:48:44]

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

[commit-bot: I haz the power, 2015-01-31 04:48:44]

Try jobs failed on following builders:
  win8_chromium_gn_rel on tryserver.chromium.win (None)

[commit-bot: I haz the power, 2015-02-03 02:48:50]

Patchset 1 (id:??) landed as
https://crrev.com/5778babeb264211044c1ff1ef6d2e41f07e341b4
Cr-Commit-Position: refs/heads/master@{#314252}

[newt (away), 2015-02-03 02:48:58]

Committed patchset #1 (id:1) manually as
5778babeb264211044c1ff1ef6d2e41f07e341b4 (presubmit successful).