Move //mojo/{public, edk} underneath //third_party

mojo/public/c/test_support/BUILD.gn

-# Copyright 2014 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# GYP version: mojo/public/mojo_public.gyp:mojo_test_support
-shared_library("test_support") {
-  output_name = "mojo_test_support"
-
-  defines = [ "MOJO_TEST_SUPPORT_IMPLEMENTATION" ]
-
-  public_configs = [ "../../build/config:mojo_sdk" ]
-
-  sources = [
-    "test_support.h",
-    "test_support_export.h",
-
-    # TODO(vtl): Convert this to thunks http://crbug.com/386799
-    "../../tests/test_support_private.cc",
-    "../../tests/test_support_private.h",
-  ]
-
-  if (is_mac) {
-    # TODO(GYP)
-    #   # Make it a run-path dependent library.
-    #   'DYLIB_INSTALL_NAME_BASE': '@loader_path',
-  }
-}