Reinitialize LocalState's CommandLinePrefStore after about_flags updates the command line.

chrome/common/json_pref_store.cc

Index: chrome/common/json_pref_store.cc
===================================================================
--- chrome/common/json_pref_store.cc	(revision 118876)
+++ chrome/common/json_pref_store.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -169,6 +169,10 @@
   observers_.RemoveObserver(observer);
 }
 
+size_t JsonPrefStore::NumberOfObservers() const {
+  return observers_.size();
+}
+
 bool JsonPrefStore::IsInitializationComplete() const {
   return initialized_;
 }