Revert of [Android]Don't check for child account/EDU device for every activity.

Revert of [Android]Don't check for child account/EDU device for every activity. (patchset #3 id:40001 of https://codereview.chromium.org/1357643002/ )

Reason for revert:
Breaks git on case-insensitive filesystems.

Original issue's description:
> [Android]Don't check for child account/EDU device for every activity.
> 
> Extract a Forced Signin Processor out of FirstRun Signin Processor which
> checks for child accounts and EDU device and is only triggered:
> -Once per Chrome Application startup.
> -On updates to accounts on the device.
> 
> Invariants:
> FRE ToS checks and FRE pending signin checks still happen on every activity for now.
> 
> Dependent patchsets:
> http://crrev.com/1341423005
> http://crrev.com/1353393002
> 
> BUG=518830
> 
> Committed: https://crrev.com/b022082dde8822156eb2fcd3a1c156b566119521
> Cr-Commit-Position: refs/heads/master@{#350133}

TBR=bauerb@chromium.org,knn@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=518830
Committed: https://chromium.googlesource.com/chromium/src/+/6cb79385a014dd500f3a81bb72db315fdb27bc12

[dcheng, 2015-09-23 23:35:55]

Created Revert of [Android]Don't check for child account/EDU device for every
activity.

[dcheng, 2015-09-23 23:36:05]

The CQ bit was unchecked by dcheng@chromium.org

[commit-bot: I haz the power, 2015-09-23 23:38:23]

Patchset 1 (id:??) landed as
https://crrev.com/6cb79385a014dd500f3a81bb72db315fdb27bc12
Cr-Commit-Position: refs/heads/master@{#350389}

[dcheng, 2015-09-23 23:38:50]

Committed patchset #1 (id:1) manually as
6cb79385a014dd500f3a81bb72db315fdb27bc12 (presubmit successful).