Don't ever attempt to upload credit cards whose numbers match.

components/autofill/core/browser/credit_card_unittest.cc

Index: components/autofill/core/browser/credit_card_unittest.cc
diff --git a/components/autofill/core/browser/credit_card_unittest.cc b/components/autofill/core/browser/credit_card_unittest.cc
index 10fa35fba3dfdb0ebf0a0a18faa1d3c11b11995d..f24726e2916fafd84ae072a9b3efc98aec7df807 100644
--- a/components/autofill/core/browser/credit_card_unittest.cc
+++ b/components/autofill/core/browser/credit_card_unittest.cc
@@ -246,6 +246,41 @@ TEST(CreditCardTest, IsLocalDuplicateOfServerCard) {
   }
 }
 
+TEST(CreditCardTest, HasSameNumberAs) {
+  CreditCard a(base::GenerateGUID(), std::string());
+  CreditCard b(base::GenerateGUID(), std::string());
+
+  // Empty cards have the same empty number.
+  EXPECT_TRUE(a.HasSameNumberAs(b));
+  EXPECT_TRUE(b.HasSameNumberAs(a));
+
+  // Same number.
+  a.set_record_type(CreditCard::LOCAL_CARD);
+  a.SetRawInfo(CREDIT_CARD_NUMBER, ASCIIToUTF16("4111111111111111"));
+  a.set_record_type(CreditCard::LOCAL_CARD);
+  b.SetRawInfo(CREDIT_CARD_NUMBER, ASCIIToUTF16("4111111111111111"));
+  EXPECT_TRUE(a.HasSameNumberAs(b));
+  EXPECT_TRUE(b.HasSameNumberAs(a));
+
+  // Local cards shouldn't match even if the last 4 are the same.
+  a.set_record_type(CreditCard::LOCAL_CARD);
+  a.SetRawInfo(CREDIT_CARD_NUMBER, ASCIIToUTF16("4111111111111111"));
+  a.set_record_type(CreditCard::LOCAL_CARD);
+  b.SetRawInfo(CREDIT_CARD_NUMBER, ASCIIToUTF16("4111222222221111"));
+  EXPECT_FALSE(a.HasSameNumberAs(b));
+  EXPECT_FALSE(b.HasSameNumberAs(a));
+
+  // Likewise if one is an unmasked server card.
+  a.set_record_type(CreditCard::FULL_SERVER_CARD);
+  EXPECT_FALSE(a.HasSameNumberAs(b));
+  EXPECT_FALSE(b.HasSameNumberAs(a));
+
+  // But if one is a masked card, then they should.
+  b.set_record_type(CreditCard::MASKED_SERVER_CARD);
+  EXPECT_TRUE(a.HasSameNumberAs(b));
+  EXPECT_TRUE(b.HasSameNumberAs(a));
+}
+
 TEST(CreditCardTest, Compare) {
   CreditCard a(base::GenerateGUID(), std::string());
   CreditCard b(base::GenerateGUID(), std::string());