message: Change the client_secret that looks like a "private key" to something more obviously fake.
diff: @@ -64,7 +64,7 @@ TEST(OAuthClientTest, GetTokenFromRefreshTokenJson) {
  const string credentials_json = R"(
  {
  "client_id": "test_client_id",
  - "client_secret": "test_client_secret",
  + "client_secret": "@@@test_client_secret@@@",
  "refresh_token": "test_refresh_token",
  "type": "authorized_user"
  })";
  @@ -75,7 +75,7 @@ TEST(OAuthClientTest, GetTokenFromRefreshTokenJson) {
  std::vector<HttpRequest*> requests({new FakeHttpRequest(
  "Uri: https://www.googleapis.com/oauth2/v3/token\n"
  "Post body: client_id=test_client_id&"
  - "client_secret=test_client_secret&"
  + "client_secret=@@@test_client_secret@@@&"
  "refresh_token=test_refresh_token&grant_type=refresh_token\n",
  kTokenJson)});
  FakeEnv env;
  