Move some of IOThread's command line logic to network_session_configurator.

components/network_session_configurator/BUILD.gn

-# Copyright 2016 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.
-
-static_library("network_session_configurator") {
-  sources = [
-    "network_session_configurator.cc",
-    "network_session_configurator.h",
-  ]
-
-  public_deps = [
-    "//base",
-    "//net",
-  ]
-
-  deps = [
-    "//components/data_reduction_proxy/core/common",
-    "//components/variations",
-    "//components/version_info",
-  ]
-}
-
-source_set("unit_tests") {
-  testonly = true
-  sources = [
-    "network_session_configurator_unittest.cc",
-  ]
-  deps = [
-    ":network_session_configurator",
-    "//base/test:test_support",
-    "//components/variations:variations",
-    "//testing/gtest",
-  ]
-}