Revert of Implement a simple ThreadChecker for Mojo and add to |internal::SharedData| and |internal::Router|.

Revert of Implement a simple ThreadChecker for Mojo and add to |internal::SharedData| and |internal::Router|. (patchset #4 id:60001 of https://codereview.chromium.org/1380043002/ )

Reason for revert:
Mandoline now crashes immediately on startup. Reverting this change locally fixes it.

(mandoline is probably doing something unsafe, but it worked previously to this patch.)

mandoline: ../../third_party/mojo/src/mojo/public/cpp/bindings/lib/shared_data.h:64: void mojo::internal::SharedData<mojo::internal::SharedPtr<mojo::Callback<void ()>::Runnable>::Impl>::Holder::Release() [T = mojo::internal::SharedPtr<mojo::Callback<void ()>::Runnable>::Impl]: Assertion `thread_checker_.CalledOnValidThread()' failed.

Original issue's description:
> Implement a simple ThreadChecker for Mojo and add to |internal::SharedData| and |internal::Router|.
>
> |internal::SharedData| is used in several places, in particular,
> callbacks, which are very easy to misuse by copying around between
> threads. |internal::Router| is used commonly between the various
> bindings classes, making it an ideal place to catch misuse of bindings.
>
> BUG=537911
>
> Committed: https://crrev.com/7cff2feae7fcccc416827013df112396c84b5017
> Cr-Commit-Position: refs/heads/master@{#352508}

TBR=rockot@chromium.org,yzshen@chromium.org,amistry@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=537911
Committed: https://crrev.com/f5b0bb898c06c6c40067d88390ccf79b675cf1d6
Cr-Commit-Position: refs/heads/master@{#352648}

[Elliot Glaysher, 2015-10-06 18:26:53]

Created Revert of Implement a simple ThreadChecker for Mojo and add to
|internal::SharedData| and |internal::Router|.