Don't run certificate algorithm mismatch tests on Sierra or later.

net/cert/cert_verify_proc_unittest.cc

Index: net/cert/cert_verify_proc_unittest.cc
diff --git a/net/cert/cert_verify_proc_unittest.cc b/net/cert/cert_verify_proc_unittest.cc
index 66ce71383cecec479eb0d24bd8a4e1f57d698332..d4a08868fb57972758bc15d7f66f23d38334b1bb 100644
--- a/net/cert/cert_verify_proc_unittest.cc
+++ b/net/cert/cert_verify_proc_unittest.cc
@@ -649,6 +649,13 @@ class CertVerifyProcInspectSignatureAlgorithmsTest : public ::testing::Test {
     LOG(INFO) << "Skipping test on iOS because certs with mismatched "
                  "algorithms cannot be imported";
     return false;
+#elif defined(OS_MACOSX)
+    if (base::mac::IsAtLeastOS10_12()) {
+      LOG(INFO) << "Skipping test on macOS >= 10.12 because certs with "
+                   "mismatched algorithms cannot be imported";
+      return false;
+    }
+    return true;
 #else
     return true;
 #endif