Added unit tests for getCredentialsFromAuthCode.

remoting/host/setup/mock_oauth_client.h

+// Copyright 2015 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 REMOTING_HOST_SETUP_MOCK_OAUTH_CLIENT_H_
+#define REMOTING_HOST_SETUP_MOCK_OAUTH_CLIENT_H_
+
+#include "remoting/host/setup/oauth_client.h"
+
+namespace remoting {
+
+class MockOAuthClient : public OAuthClient {
+ public:
+  MockOAuthClient(const std::string& user_email,
+                  const std::string& refresh_token);
+
+  ~MockOAuthClient() override;
+
+  void GetCredentialsFromAuthCode(
+      const gaia::OAuthClientInfo& oauth_client_info,
+      const std::string& auth_code,
+      bool need_user_email,
+      CompletionCallback on_done) override;
+
+ private:
+  std::string user_email_;
+  std::string refresh_token_;
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_SETUP_MOCK_OAUTH_CLIENT_H_