[Autofill] Correctly fill month selects where the first value is negative.

components/autofill/core/browser/autofill_field_unittest.cc

 // Copyright 2013 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.
 
 #include "components/autofill/core/browser/autofill_field.h"
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 544 matching lines @@
        NotNumericMonthsContentsWithPlaceholder()},
       // Values start at 01 and the first content is a placeholder.
       {{"01", "02", "03", "04", "05", "06", "07", "08", "09", "10", "11", "12",
         "13"},
        NotNumericMonthsContentsWithPlaceholder()},
       // Values start at 0 after a placeholder.
       {{"?", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11"},
        NotNumericMonthsContentsWithPlaceholder()},
       // Values start at 1 after a placeholder.
       {{"?", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"},
+       NotNumericMonthsContentsWithPlaceholder()},
+      // Values start at 0 after a negative number.
+      {{"-1", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11"},
+       NotNumericMonthsContentsWithPlaceholder()},
+      // Values start at 1 after a negative number.
+      {{"-1", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12"},
        NotNumericMonthsContentsWithPlaceholder()}};
 
   for (TestCase test_case : test_cases) {
     ASSERT_EQ(test_case.select_values.size(), test_case.select_contents.size());
 
     TestFillingExpirationMonth(test_case.select_values,
                                test_case.select_contents,
                                test_case.select_values.size());
   }
 }
@@ skipping 298 matching lines @@
   EXPECT_EQ(-1, ret);
 
   // Case 7: No match (not present)
   ret = AutofillField::FindShortestSubstringMatchInSelect(
       ASCIIToUTF16("Canadia"), true, &field);
   EXPECT_EQ(-1, ret);
 }
 
 }  // namespace
 }  // namespace autofill