[ios] RootCoordinator and view controller.

ios/clean/chrome/browser/ui/root/BUILD.gn

+# Copyright 2017 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.
+
+source_set("root") {
+  sources = [
+    "root_coordinator.h",
+    "root_coordinator.mm",
+  ]
+  deps = [
+    ":root_ui",
+    "//ios/clean/chrome/browser",
+    "//ios/clean/chrome/browser/ui/commands",
+    "//ios/clean/chrome/browser/ui/tab_grid",
+    "//ios/shared/chrome/browser/ui/browser_list",
+    "//ios/shared/chrome/browser/ui/commands",
+    "//ios/shared/chrome/browser/ui/coordinators",
+  ]
+  configs += [ "//build/config/compiler:enable_arc" ]
+}
+
+source_set("root_ui") {
+  sources = [
+    "root_container_view_controller.h",
+    "root_container_view_controller.mm",
+  ]
+  deps = [
+    "//base",
+    "//ios/clean/chrome/browser/ui/animators",
+  ]
+  configs += [ "//build/config/compiler:enable_arc" ]
+}
+
+source_set("unit_tests") {
+  sources = [
+    "root_container_view_controller_unittest.mm",
+    "root_coordinator_unittest.mm",
+  ]
+  deps = [
+    ":root",
+    ":root_ui",
+    "//base/test:test_support",
+    "//ios/clean/chrome/browser",
+    "//ios/clean/chrome/browser/ui/animators",
+    "//testing/gtest",
+    "//third_party/ocmock",
+  ]
+  configs += [ "//build/config/compiler:enable_arc" ]
+  testonly = true
+}