message: Update generate_diff_report.cc
diff: @@ -12,7 +12,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  ==============================================================================*/
  -
  +#include <string>
  #include <vector>
  #include "tensorflow/core/util/command_line_flags.h"
  