ScreenContext is moved to components/login.

ScreenContext is moved to components/login.

BUG=405876
TEST=existing unit_tests and browser_tests

Committed: https://crrev.com/98f956e5159865dd1f61539ff7f9fe01e453ed3c
Cr-Commit-Position: refs/heads/master@{#301131}

[ygorshenin1, 2014-10-23 18:32:00]

ygorshenin@chromium.org changed reviewers:
+ jochen@chromium.org, nkostylev@chromium.org

[jochen (gone - plz use gerrit), 2014-10-24 11:39:46]

lgtm

[Nikita (slow), 2014-10-24 14:41:45]

lgtm

[ygorshenin1, 2014-10-24 14:44:15]

The CQ bit was checked by ygorshenin@chromium.org

[commit-bot: I haz the power, 2014-10-24 14:45:55]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/672203003/40001

[commit-bot: I haz the power, 2014-10-24 14:51:00]

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

[commit-bot: I haz the power, 2014-10-24 14:51:01]

Try jobs failed on following builders:
  mac_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu/builds/73165)
  android_arm64_dbg_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_arm64_d...)
  ios_rel_device_ninja on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_ni...)
  mac_chromium_rel on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel/...)
  win_chromium_x64_rel on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_x64_...)

[ygorshenin1, 2014-10-24 16:15:51]

The CQ bit was checked by ygorshenin@chromium.org

[commit-bot: I haz the power, 2014-10-24 16:16:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/672203003/60001

[commit-bot: I haz the power, 2014-10-24 17:22:29]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2014-10-24 17:23:09]

Patchset 4 (id:??) landed as
https://crrev.com/98f956e5159865dd1f61539ff7f9fe01e453ed3c
Cr-Commit-Position: refs/heads/master@{#301131}