Update some uses of Value in chrome/browser to use the base:: namespace.

chrome/browser/prefs/browser_prefs.cc

 // Copyright 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 "chrome/browser/prefs/browser_prefs.h"
 
 #include "apps/prefs.h"
 #include "base/debug/trace_event.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
@@ skipping 441 matching lines @@
 #endif
 
 #if defined(USE_ASH)
   ash::RegisterChromeLauncherUserPrefs(registry);
 #endif
 
   // Prefs registered only for migration (clearing or moving to a new
   // key) go here.
   registry->RegisterDictionaryPref(
       kBackupPref,
-      new DictionaryValue(),
+      new base::DictionaryValue(),
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 #if !defined(OS_ANDROID)
   registry->RegisterStringPref(
       kSyncPromoErrorMessage,
       std::string(),
       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 #endif
 }
 
 void RegisterUserProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
@@ skipping 91 matching lines @@
     local_state->SetInteger(prefs::kMultipleProfilePrefMigration,
                             current_version);
   }
 
 #if defined(OS_CHROMEOS)
   chromeos::default_pinned_apps_field_trial::MigratePrefs(local_state);
 #endif
 }
 
 }  // namespace chrome