Delete the PreferenceMACs on profile deletion.

components/prefs/json_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/json_pref_store.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <utility>
@@ skipping 366 matching lines @@
           &PostWriteCallback, callbacks.second,
           base::Bind(&JsonPrefStore::RunOrScheduleNextSuccessfulWriteCallback,
                      AsWeakPtr()),
           base::SequencedTaskRunnerHandle::Get()));
 }
 
 void JsonPrefStore::ClearMutableValues() {
   NOTIMPLEMENTED();
 }
 
+void JsonPrefStore::OnStoreDeletionFromDisk() {
+  if (pref_filter_)
+    pref_filter_->OnStoreDeletionFromDisk();
+}
+
 void JsonPrefStore::OnFileRead(std::unique_ptr<ReadResult> read_result) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
 
   DCHECK(read_result);
 
   std::unique_ptr<base::DictionaryValue> unfiltered_prefs(
       new base::DictionaryValue);
 
   read_error_ = read_result->error;
 
@@ skipping 191 matching lines @@
   DCHECK_EQ(31, num_buckets);
 
   // The histogram below is an expansion of the UMA_HISTOGRAM_CUSTOM_COUNTS
   // macro adapted to allow for a dynamically suffixed histogram name.
   // Note: The factory creates and owns the histogram.
   base::HistogramBase* histogram = base::Histogram::FactoryGet(
       histogram_name, min_value, max_value, num_buckets,
       base::HistogramBase::kUmaTargetedHistogramFlag);
   return histogram;
 }