GitLab

Initial checkin for the app remoting test driver tool.  The external pieces of the test driver will consist of a common library which will build the dependencies and core helper classes and a minimal version of the tool which will include a minimal number of tests.  An internal version of the tool will include the common library and pull in additional tests from src-internal.

The tool uses the GTest framework and this CL is to set up the foundation
so I can start adding functionality.  I am not hooking it into the public gyp
files yet, that will come in a future change as more changes to the
remoting GYP files are expected.

BUG=

Review URL: https://codereview.chromium.org/900973002

Cr-Commit-Position: refs/heads/master@{#314712}