Delete the PreferenceMACs on profile deletion.

components/prefs/testing_pref_store.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 "components/prefs/testing_pref_store.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/json/json_writer.h"
@@ skipping 161 matching lines @@
   DCHECK(!init_complete_);
   block_async_read_ = block_async_read;
   if (pending_async_read_ && !block_async_read_)
     NotifyInitializationCompleted();
 }
 
 void TestingPrefStore::ClearMutableValues() {
   NOTIMPLEMENTED();
 }
 
+void TestingPrefStore::OnStoreDeletionFromDisk() {
+  NOTIMPLEMENTED();

[gab, 2017/06/08 16:14:28]

That results in a log warning, in this case I think the right impl is actually
an empty body, so remove NOTIMPLEMENTED()

[proberge, 2017/06/08 18:32:59]

Done.

+}
+
 void TestingPrefStore::set_read_only(bool read_only) {
   read_only_ = read_only;
 }
 
 void TestingPrefStore::set_read_success(bool read_success) {
   DCHECK(!init_complete_);
   read_success_ = read_success;
 }
 
 void TestingPrefStore::set_read_error(
     PersistentPrefStore::PrefReadError read_error) {
   DCHECK(!init_complete_);
   read_error_ = read_error;
 }
 
 TestingPrefStore::~TestingPrefStore() {
   for (auto& pref : prefs_) {
     CheckPrefIsSerializable(pref.first, *pref.second);
   }
 }
 
 void TestingPrefStore::CheckPrefIsSerializable(const std::string& key,
                                                const base::Value& value) {
   std::string json;
   EXPECT_TRUE(base::JSONWriter::Write(value, &json))
       << "Pref \"" << key << "\" is not serializable as JSON.";
 }