Store a stacktrace of PrefService destruction in PrefChangeRegistrar

base/prefs/pref_change_registrar.h

 // Copyright (c) 2010 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 BASE_PREFS_PREF_CHANGE_REGISTRAR_H_
 #define BASE_PREFS_PREF_CHANGE_REGISTRAR_H_
 
 #include <map>
 #include <string>
 
@@ skipping 48 matching lines @@
   bool IsManaged();
 
   // Return the PrefService for this registrar.
   PrefService* prefs();
   const PrefService* prefs() const;
 
  private:
   // PrefObserver:
   virtual void OnPreferenceChanged(PrefService* service,
                                    const std::string& pref_name) OVERRIDE;
+  // TODO(battre): Remove function (debugging tool for crbug.com/373435).

[engedy, 2014/05/16 15:19:58]

nit: I am not sure saying "debugging tool" is too informative. The same way you
are doing it in some other places, could we just consistently say everywhere:
 
// TODO(battre): Remove function. See: crbug.com/373435.

And add some details to the bug itself. Anyone interested can then look up the
bug for a detailed explanation.

[battre, 2014/05/16 15:58:37]

Done.

+  virtual void SetPrefServiceDestructionTrace(
+      const std::string& stacktrace) OVERRIDE;
 
   static void InvokeUnnamedCallback(const base::Closure& callback,
                                     const std::string& pref_name);
 
   typedef std::map<std::string, NamedChangeCallback> ObserverMap;
 
   ObserverMap observers_;
   PrefService* service_;
+  // TODO(battre): Remove attribute (debugging tool for crbug.com/373435).
+  std::string pref_service_destruction_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefChangeRegistrar);
 };
 
 #endif  // BASE_PREFS_PREF_CHANGE_REGISTRAR_H_