Integrate registry_hash_store_contents with the rest of tracked prefs.

components/prefs/json_pref_store.h

 // 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.
 
 #ifndef COMPONENTS_PREFS_JSON_PREF_STORE_H_
 #define COMPONENTS_PREFS_JSON_PREF_STORE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 88 matching lines @@
   PrefReadError ReadPrefs() override;
   void ReadPrefsAsync(ReadErrorDelegate* error_delegate) override;
   void CommitPendingWrite() override;
   void SchedulePendingLossyWrites() override;
   void ReportValueChanged(const std::string& key, uint32_t flags) override;
 
   // Just like RemoveValue(), but doesn't notify observers. Used when doing some
   // cleanup that shouldn't otherwise alert observers.
   void RemoveValueSilently(const std::string& key, uint32_t flags);
 
-  // Registers |on_next_successful_write| to be called once, on the next
+  // Registers |on_next_successful_write_reply| to be called once, on the next
   // successful write event of |writer_|.
-  void RegisterOnNextSuccessfulWriteCallback(
-      const base::Closure& on_next_successful_write);
+  void RegisterOnNextSuccessfulWriteReply(
+      const base::Closure& on_next_successful_write_reply);
+
+  // Registers |on_next_successful_write| to be synchronously invoked on the
+  // next successful write event of |writer|.

[gab, 2016/08/08 04:37:45]

Description and var names are no longer up-to-date.

[proberge, 2016/08/31 17:30:16]

Done.

+  void RegisterOnNextWriteSynchronousCallback(
+      const base::Callback<void(bool success)>& on_next_write_callback);
 
   void ClearMutableValues() override;
 
  private:
   // Represents a histogram for recording the number of writes to the pref file
   // that occur every kHistogramWriteReportIntervalInMins minutes.
   class COMPONENTS_PREFS_EXPORT WriteCountHistogram {
    public:
     static const int32_t kHistogramWriteReportIntervalMins;
 
@@ skipping 99 matching lines @@
   PrefReadError read_error_;
 
   std::set<std::string> keys_need_empty_value_;
 
   WriteCountHistogram write_count_histogram_;
 
   DISALLOW_COPY_AND_ASSIGN(JsonPrefStore);
 };
 
 #endif  // COMPONENTS_PREFS_JSON_PREF_STORE_H_