cros: Make sure views-based lock screen is destroyed after it is dismissed.

ash/login/mock_lock_screen_client.h

 // 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.
 
 #ifndef ASH_LOGIN_MOCK_LOCK_SCREEN_CLIENT_H_
 #define ASH_LOGIN_MOCK_LOCK_SCREEN_CLIENT_H_
 
 #include "ash/public/interfaces/lock_screen.mojom.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 namespace ash {
 
 class MockLockScreenClient : public mojom::LockScreenClient {
  public:
   MockLockScreenClient();
   ~MockLockScreenClient() override;
 
   mojom::LockScreenClientPtr CreateInterfacePtrAndBind();
 
-  // mojom::LockScreenClient:
-  MOCK_METHOD3(AuthenticateUser,
+  MOCK_METHOD4(AuthenticateUser_,
                void(const AccountId& account_id,
                     const std::string& password,
-                    bool authenticated_by_pin));
+                    bool authenticated_by_pin,
+                    AuthenticateUserCallback& callback));
+
+  // Set the result that should be passed to |callback| in |AuthenticateUser|.
+  void set_authenticate_user_callback_result(bool value) {
+    authenticate_user_callback_result_ = value;
+  }
+
+  // mojom::LockScreenClient:
+  void AuthenticateUser(const AccountId& account_id,
+                        const std::string& password,
+                        bool authenticated_by_pin,
+                        AuthenticateUserCallback callback) override;
   MOCK_METHOD1(AttemptUnlock, void(const AccountId& account_id));
   MOCK_METHOD1(HardlockPod, void(const AccountId& account_id));
   MOCK_METHOD1(RecordClickOnLockIcon, void(const AccountId& account_id));
 
  private:
+  bool authenticate_user_callback_result_ = true;
+
   mojo::Binding<ash::mojom::LockScreenClient> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(MockLockScreenClient);
 };
 
 // Helper method to bind a lock screen client so it receives all mojo calls.
 std::unique_ptr<MockLockScreenClient> BindMockLockScreenClient();
 
 }  // namespace ash
 
-#endif  // ASH_LOGIN_MOCK_LOCK_SCREEN_CLIENT_H_
+#endif  // ASH_LOGIN_MOCK_LOCK_SCREEN_CLIENT_H_