Fix a division by zero when multiplying 0 * y with SafeNumerics.

base/numerics/safe_numerics_unittest.cc

Index: base/numerics/safe_numerics_unittest.cc
diff --git a/base/numerics/safe_numerics_unittest.cc b/base/numerics/safe_numerics_unittest.cc
index bdececb19364c75b2eb9813ec4c6467f529f34d9..3185b06faf08753110dc5c67d34d9c69a28fb760 100644
--- a/base/numerics/safe_numerics_unittest.cc
+++ b/base/numerics/safe_numerics_unittest.cc
@@ -239,6 +239,9 @@ static void TestArithmetic(const char* dst, int line) {
   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>() * 1));
   TEST_EXPECTED_VALUE(1, (CheckedNumeric<Dst>(1) * 1));
   TEST_EXPECTED_VALUE(-2, (CheckedNumeric<Dst>(-1) * 2));
+  TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(0) * 0));
+  TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(-1) * 0));
+  TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(0) * -1));
   TEST_EXPECTED_VALIDITY(
       RANGE_OVERFLOW, CheckedNumeric<Dst>(DstLimits::max()) * DstLimits::max());