Disable TwoClientPasswordsSyncTest.SetPassphraseAndThenSetupSync on Mac.

chrome/browser/sync/test/integration/two_client_passwords_sync_test.cc

 // Copyright (c) 2012 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 <stdint.h>
 
 #include <limits>
 
 #include "base/guid.h"
 #include "base/hash.h"
@@ skipping 125 matching lines @@
 
   RemoveLogin(GetPasswordStore(1), form0);
   RemoveLogin(GetVerifierPasswordStore(), form0);
   ASSERT_EQ(1, GetVerifierPasswordCount());
 
   // Wait for deletion from client 1 to propagate.
   ASSERT_TRUE(AwaitProfileContainsSamePasswordFormsAsVerifier(0));
   ASSERT_TRUE(AllProfilesContainSamePasswordFormsAsVerifier());
 }
 
+// Flaky on Mac: https://crbug.com/639449
+#if defined(OS_MACOSX)
+#define MAYBE_SetPassphraseAndThenSetupSync DISABLED_SetPassphraseAndThenSetupSync
+#else
+#define MAYBE_SetPassphraseAndThenSetupSync SetPassphraseAndThenSetupSync
+#endif
 IN_PROC_BROWSER_TEST_F(TwoClientPasswordsSyncTest,
-                       SetPassphraseAndThenSetupSync) {
+                       MAYBE_SetPassphraseAndThenSetupSync) {
   ASSERT_TRUE(SetupClients());
 
   ASSERT_TRUE(GetClient(0)->SetupSync());
   SetEncryptionPassphrase(0, kValidPassphrase, ProfileSyncService::EXPLICIT);
   ASSERT_TRUE(AwaitPassphraseAccepted(GetSyncService(0)));
 
   // When client 1 hits a passphrase required state, we can infer that
   // client 0's passphrase has been committed. to the server.
   ASSERT_FALSE(GetClient(1)->SetupSync());
   ASSERT_TRUE(AwaitPassphraseRequired(GetSyncService(1)));
@@ skipping 100 matching lines @@
 
   // Blocks and waits for password forms in all profiles to match.
   ASSERT_TRUE(AwaitAllProfilesContainSamePasswordForms());
 
   // Check that total number of passwords is as expected.
   for (int i = 0; i < num_clients(); ++i) {
     ASSERT_EQ(GetPasswordCount(i), init_password_count + num_clients()) <<
         "Total password count is wrong.";
   }
 }