Re-enable preferences service access for browser+ash

chrome/browser/prefs/preferences_service.cc

 // Copyright 2016 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 "chrome/browser/prefs/preferences_service.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
@@ skipping 15 matching lines @@
 
 PreferencesService::~PreferencesService() {}
 
 void PreferencesService::PreferenceChanged(const std::string& preference_name) {
   if (setting_preferences_)
     return;
   const PrefService::Preference* pref =
       service_->FindPreference(preference_name);
   std::unique_ptr<base::DictionaryValue> dictionary =
       base::MakeUnique<base::DictionaryValue>();
-  dictionary->Set(preference_name, pref->GetValue()->CreateDeepCopy());
+  dictionary->SetWithoutPathExpansion(preference_name,
+                                      pref->GetValue()->CreateDeepCopy());
   client_->OnPreferencesChanged(std::move(dictionary));
 }
 
 void PreferencesService::SetPreferences(
     std::unique_ptr<base::DictionaryValue> preferences) {
   DCHECK(!setting_preferences_);
   // We ignore preference changes caused by us.
   base::AutoReset<bool> setting_preferences(&setting_preferences_, true);
   for (base::DictionaryValue::Iterator it(*preferences); !it.IsAtEnd();
        it.Advance()) {
@@ skipping 19 matching lines @@
     if (!pref) {
       DLOG(ERROR) << "Preference " << it << " not found.\n";
       continue;
     }
     // PreferenceManager lifetime is managed by a mojo::StrongBindingPtr owned
     // by PreferenceConnectionManager. It will outlive
     // |preferences_change_registrar_| which it owns.
     preferences_change_registrar_->Add(
         it, base::Bind(&PreferencesService::PreferenceChanged,
                        base::Unretained(this)));
-    dictionary->Set(it, pref->GetValue()->CreateDeepCopy());
+    dictionary->SetWithoutPathExpansion(it, pref->GetValue()->CreateDeepCopy());
   }
 
   if (dictionary->empty())
     return;
   client_->OnPreferencesChanged(std::move(dictionary));
 }