Delete the PreferenceMACs on profile deletion.

services/preferences/pref_store_consistency_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 <utility>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
@@ skipping 138 matching lines @@
                     const std::vector<std::string>& path) override {
     writes_.push_back({std::vector<mojom::PrefUpdatePtr>(), {key, path}});
     if (writes_.size() == expected_writes_) {
       expected_writes_ = 0;
       std::move(stop_).Run();
     }
   }
   void CommitPendingWrite(base::OnceClosure) override {}
   void SchedulePendingLossyWrites() override {}
   void ClearMutableValues() override {}
+  void OnStoreDeletionFromDisk() override {}
 
   // mojom::PrefStoreObserver
   void OnPrefsChanged(std::vector<mojom::PrefUpdatePtr> updates) override {
     updates_.push_back({std::move(updates), false});
     if (updates_.size() == expected_updates_) {
       expected_updates_ = 0;
       std::move(stop_).Run();
     }
   }
   void OnInitializationCompleted(bool succeeded) override { NOTREACHED(); }
@@ skipping 738 matching lines @@
 
   connection2->ForwardUpdates(1);
   EXPECT_EQ(empty_dict, *pref_service2.GetDictionary(kDictionaryKey));
 
   connection2->ForwardUpdates(1);
   EXPECT_EQ(empty_dict, *pref_service2.GetDictionary(kDictionaryKey));
 }
 
 }  // namespace
 }  // namespace prefs