Delete the PreferenceMACs on profile deletion.

services/preferences/public/cpp/tests/persistent_pref_store_client_unittest.cc

 // Copyright 2017 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 "services/preferences/public/cpp/persistent_pref_store_client.h"
 
 #include <utility>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
@@ skipping 81 matching lines @@
   void RequestValue(const std::string& key,
                     const std::vector<std::string>& path) override {}
 
   void CommitPendingWrite(CommitPendingWriteCallback callback) override {
     base::SequencedTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                      std::move(callback));
   }
 
   void SchedulePendingLossyWrites() override {}
   void ClearMutableValues() override {}
+  void OnStoreDeletionFromDisk() override {}
 
   base::MessageLoop message_loop_;
 
   std::unique_ptr<PrefService> pref_service_;
 
   mojo::Binding<mojom::PersistentPrefStore> binding_;
 
   std::vector<mojom::PrefUpdatePtr> last_updates_;
   base::OnceClosure on_update_;
 
@@ skipping 374 matching lines @@
   auto update = WaitForUpdate();
   ASSERT_TRUE(update->is_split_updates());
   auto& split_updates = update->get_split_updates();
   ASSERT_EQ(1u, split_updates.size());
   EXPECT_EQ(base::Value(2), *split_updates[0]->value);
   EXPECT_EQ((std::vector<std::string>{"path"}), split_updates[0]->path);
 }
 
 }  // namespace
 }  // namespace prefs