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

mojo/public/mojo.gni

-# 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.
-
-declare_args() {
-  # Whether to use a prebuilt mojo_shell binary instead of one built from
-  # source.
-  use_prebuilt_mojo_shell = false
-
-  # Whether to build the dart bindings.
-  mojo_use_dart = false
-}
-
-# The absolute path to the directory containing the mojo public SDK (i.e., the
-# directory containing mojo/public). The build files within the Mojo public
-# SDK use this variable to allow themselves to be parameterized by the location
-# of the public SDK within a client repo.
-mojo_root = get_path_info("../..", "abspath")