[ios] RootCoordinator and view controller.

ios/clean/chrome/app/steps/BUILD.gn

Index: ios/clean/chrome/app/steps/BUILD.gn
diff --git a/ios/clean/chrome/app/steps/BUILD.gn b/ios/clean/chrome/app/steps/BUILD.gn
index 7da46f086a8abc03343e1f584fc1e3664514d812..e1b13773cb934bab6774c915ed95062209cd1bd7 100644
--- a/ios/clean/chrome/app/steps/BUILD.gn
+++ b/ios/clean/chrome/app/steps/BUILD.gn
@@ -10,8 +10,8 @@ source_set("steps") {
     "launch_to_basic.mm",
     "launch_to_foreground.h",
     "launch_to_foreground.mm",
-    "tab_grid_coordinator+application_step.h",
-    "tab_grid_coordinator+application_step.mm",
+    "root_coordinator+application_step.h",
+    "root_coordinator+application_step.mm",
   ]
 
   configs += [ "//build/config/compiler:enable_arc" ]
@@ -28,10 +28,27 @@ source_set("steps") {
     "//ios/chrome/browser/content_settings",
     "//ios/chrome/browser/web:web_internal",
     "//ios/clean/chrome/app:application_state",
-    "//ios/clean/chrome/browser/ui/tab_grid",
+    "//ios/clean/chrome/browser/ui/root",
     "//ios/net",
     "//ios/shared/chrome/browser/ui/browser_list",
     "//ios/shared/chrome/browser/ui/coordinators",
     "//ios/web:web_arc",
   ]
 }
+
+source_set("unit_tests") {
+  testonly = true
+
+  sources = [
+    "root_coordinator+application_step_unittest.mm",
+  ]
+
+  configs += [ "//build/config/compiler:enable_arc" ]
+
+  deps = [
+    ":steps",
+    "//base/test:test_support",
+    "//testing/gtest",
+    "//third_party/ocmock",
+  ]
+}