Refactor Pickle Read methods to use higher performance PickleIterator.

ipc/param_traits_macros.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 IPC_PARAM_TRAITS_MACROS_H_
 #define IPC_PARAM_TRAITS_MACROS_H_
 
 #include <string>
 
 // Traits generation for structs.
 #define IPC_STRUCT_TRAITS_BEGIN(struct_name) \
   namespace IPC { \
     template <> \
     struct IPC_MESSAGE_EXPORT ParamTraits<struct_name> { \
       typedef struct_name 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); \
     }; \
   }
 
 #define IPC_STRUCT_TRAITS_MEMBER(name)
 #define IPC_STRUCT_TRAITS_PARENT(type)
 #define IPC_STRUCT_TRAITS_END()
 
 // Traits generation for enums.
 #define IPC_ENUM_TRAITS(enum_name) \
   namespace IPC { \
     template <> \
     struct IPC_MESSAGE_EXPORT ParamTraits<enum_name> { \
       typedef enum_name 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); \
     }; \
   }
 
 #endif  // IPC_PARAM_TRAITS_MACROS_H_