Add the Mojo implementation of authenticator.mojom's MakeCredential.

content/test/BUILD.gn

 # 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
@@ skipping 1330 matching lines @@
     "../browser/web_contents/aura/overscroll_navigation_overlay_unittest.cc",
     "../browser/web_contents/aura/overscroll_window_animation_unittest.cc",
     "../browser/web_contents/aura/overscroll_window_delegate_unittest.cc",
     "../browser/web_contents/web_contents_delegate_unittest.cc",
     "../browser/web_contents/web_contents_impl_unittest.cc",
     "../browser/web_contents/web_contents_user_data_unittest.cc",
     "../browser/web_contents/web_contents_view_aura_unittest.cc",
     "../browser/web_contents/web_contents_view_mac_unittest.mm",
     "../browser/web_contents/web_drag_dest_mac_unittest.mm",
     "../browser/web_contents/web_drag_source_mac_unittest.mm",
+    "../browser/webauth/authenticator_impl_unittest.cc",
     "../browser/websockets/websocket_manager_unittest.cc",
     "../browser/webui/i18n_source_stream_unittest.cc",
     "../browser/webui/url_data_manager_backend_unittest.cc",
     "../browser/webui/web_ui_data_source_unittest.cc",
     "../browser/webui/web_ui_message_handler_unittest.cc",
     "../child/blink_platform_impl_unittest.cc",
     "../child/blob_storage/blob_consolidation_unittest.cc",
     "../child/blob_storage/blob_transport_controller_unittest.cc",
     "../child/dwrite_font_proxy/dwrite_font_proxy_win_unittest.cc",
     "../child/dwrite_font_proxy/font_fallback_win_unittest.cc",
@@ skipping 544 matching lines @@
   if (is_android) {
     deps += [ "//testing/android/native_test:native_test_native_code" ]
   }
 }
 
 group("fuzzers") {
   deps = [
     "//content/test/fuzzer",
   ]
 }