Get rid of PrefService::GetMutableDictionary/GetMutableList

content/browser/host_zoom_map.cc

 // Copyright (c) 2011 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 <cmath>
 
 #include "content/browser/host_zoom_map.h"
 
 #include "base/string_piece.h"
 #include "base/utf_string_conversions.h"
@@ skipping 109 matching lines @@
                                          Source<Profile>(profile_),
                                          NotificationService::NoDetails());
 
   // If we're in incognito mode, don't persist changes to the prefs.  We'll keep
   // them in memory only so they will be forgotten on exiting incognito.
   if (profile_->IsOffTheRecord())
     return;
 
   updating_preferences_ = true;
   {
-    ScopedUserPrefUpdate update(profile_->GetPrefs(),
+    DictionaryPrefUpdate update(profile_->GetPrefs(),
                                 prefs::kPerHostZoomLevels);
-    DictionaryValue* host_zoom_dictionary =
-        profile_->GetPrefs()->GetMutableDictionary(prefs::kPerHostZoomLevels);
+    DictionaryValue* host_zoom_dictionary = update.Get();
     if (level == default_zoom_level_) {
       host_zoom_dictionary->RemoveWithoutPathExpansion(host, NULL);
     } else {
       host_zoom_dictionary->SetWithoutPathExpansion(
           host, Value::CreateDoubleValue(level));
     }
   }
   updating_preferences_ = false;
 }
 
@@ skipping 109 matching lines @@
       break;
     }
     default:
       NOTREACHED() << "Unexpected preference observed.";
   }
 }
 
 HostZoomMap::~HostZoomMap() {
   Shutdown();
 }