Added unit tests for getCredentialsFromAuthCode.

remoting/host/setup/mock_oauth_client.h

Index: remoting/host/setup/mock_oauth_client.h
diff --git a/remoting/host/setup/mock_oauth_client.h b/remoting/host/setup/mock_oauth_client.h
new file mode 100644
index 0000000000000000000000000000000000000000..db235a5fceb7d8a0437e0d9a65715b7251fd5a22
--- /dev/null
+++ b/remoting/host/setup/mock_oauth_client.h
@@ -0,0 +1,32 @@
+// 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_