Refactor Pickle Read methods to use higher performance PickleIterator.

chrome/common/common_param_traits.h

-// 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.
 
 #ifndef CHROME_COMMON_COMMON_PARAM_TRAITS_H_
 #define CHROME_COMMON_COMMON_PARAM_TRAITS_H_
 #pragma once
 
 #include <string>
 
 #include "chrome/common/content_settings.h"
 #include "ipc/ipc_param_traits.h"
 
+class PickleIterator;
+
 namespace IPC {
 
 class Message;
 
 template <>
 struct ParamTraits<ContentSetting> {
   typedef ContentSetting param_type;
   static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, void** iter, param_type* p);
+  static bool Read(const Message* m, PickleIterator* iter, param_type* p);
   static void Log(const param_type& p, std::string* l);
 };
 
 template <>
 struct ParamTraits<ContentSettingsType> {
   typedef ContentSettingsType param_type;
   static void Write(Message* m, const param_type& p);
-  static bool Read(const Message* m, void** iter, param_type* p);
+  static bool Read(const Message* m, PickleIterator* iter, param_type* p);
   static void Log(const param_type& p, std::string* l);
 };
 
 }  // namespace IPC
 
 #endif  // CHROME_COMMON_COMMON_PARAM_TRAITS_H_