Create FakeProviders for NativeAppMetadata and NativeAppManager

ios/public/provider/chrome/browser/native_app_launcher/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.
 
 source_set("native_app_launcher") {
   sources = [
     "native_app_metadata.h",
     "native_app_types.h",
     "native_app_whitelist_manager.h",
   ]
+  configs += [ "//build/config/compiler:enable_arc" ]
 }
+
+source_set("test_support") {
+  testonly = true
+  sources = [
+    "fake_native_app_metadata.h",
+    "fake_native_app_metadata.mm",
+    "fake_native_app_whitelist_manager.h",
+    "fake_native_app_whitelist_manager.mm",
+  ]
+  deps = [
+    "//base",
+    "//ios/public/provider/chrome/browser",
+    "//url",
+  ]
+  configs += [ "//build/config/compiler:enable_arc" ]
+}