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

components/webauth/authenticator_web_contents_manager_unittest.cc

+// 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.
+
+#include "components/webauth/authenticator_web_contents_manager.h"
+
+#include "components/webauth/authenticator_impl.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/test/test_renderer_host.h"
+#include "content/test/test_render_frame_host.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using ::testing::_;
+
+using webauth::mojom::AuthenticatorPtr;
+
+class AuthenticatorManagerTest : public content::RenderViewHostTestHarness {
+ public:
+  AuthenticatorManagerTest() {}
+  ~AuthenticatorManagerTest() override {}
+};
+
+// Test that the manager can be created.
+TEST_F(AuthenticatorManagerTest, CreateForWebContents) {
+  AuthenticatorWebContentsManager* manager =
+      AuthenticatorWebContentsManager::GetOrCreateForWebContents(
+          web_contents());
+  ASSERT_NE(manager, nullptr);
+}
+
+// Test that the manager creates an authenticator.
+TEST_F(AuthenticatorManagerTest, CreateAuthenticator) {
+  AuthenticatorPtr authenticator;
+  AuthenticatorPtr nullInterface;
+  AuthenticatorWebContentsManager::GetOrCreateForWebContents(web_contents())
+      ->CreateAuthenticator(main_rfh(), mojo::MakeRequest(&authenticator));
+  EXPECT_FALSE(authenticator.Equals(nullInterface));
+}
+
+// Test that the same AuthenticatorManager is returned for the same web content.
+TEST_F(AuthenticatorManagerTest, MultipleManagers) {
+  AuthenticatorWebContentsManager* manager =
+      AuthenticatorWebContentsManager::GetOrCreateForWebContents(
+          web_contents());
+  AuthenticatorWebContentsManager* manager2 =
+      AuthenticatorWebContentsManager::GetOrCreateForWebContents(
+          web_contents());
+  EXPECT_TRUE(manager == manager2);
+}