Add base namespace to more values in sync and elsewhere.

sync/js/js_arg_list.cc

 // 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.
 
 #include "sync/js/js_arg_list.h"
 
 #include "base/json/json_writer.h"
 
 namespace syncer {
 
 JsArgList::JsArgList() {}
 
-JsArgList::JsArgList(ListValue* args) : args_(args) {}
+JsArgList::JsArgList(base::ListValue* args) : args_(args) {}
 
 JsArgList::~JsArgList() {}
 
-const ListValue& JsArgList::Get() const {
+const base::ListValue& JsArgList::Get() const {
   return args_.Get();
 }
 
 std::string JsArgList::ToString() const {
   std::string str;
   base::JSONWriter::Write(&Get(), &str);
   return str;
 }
 
 }  // namespace syncer