Move remaining test targets out of //mojo/public.

Move remaining test targets out of //mojo/public.

The test targets currently in //mojo/public depend on the EDK to run and thus
are not part of the public SDK. This CL converts the remaining test targets in
the public SDK into testonly mojo_sdk_source_sets, and adds new test targets
under the EDK that depend on the corresponding source_sets as well as the EDK
mechanism for running the unittests.

Note that the dependencies from the test targets to the source_sets are
specified via relative paths as part of the work toward having the EDK be
flexible wrt its location in a client repo.

BUG=439082

[blundell, 2014-12-09 07:59:08]

blundell@chromium.org changed reviewers:
+ jamesr@chromium.org

[blundell, 2014-12-10 22:51:51]

friendly ping

[blundell, 2014-12-12 17:17:45]

qsr@ is going to take charge of this while I'm out.

[jamesr, 2014-12-13 01:36:30]

The gyp changes and comments don't apply any more, but otherwise lgtm

[qsr, 2014-12-15 09:12:51]

On 2014/12/13 01:36:30, jamesr wrote:
> The gyp changes and comments don't apply any more, but otherwise lgtm

Removed gyp comments. Moved the CL to:
https://codereview.chromium.org/796853003/