Refactor Pickle Read methods to use higher performance PickleIterator.

ipc/ipc_sync_message.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 "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 #include <stack>
@@ skipping 56 matching lines @@
   set_pump_messages_event(dummy_event.Pointer());
 }
 
 bool SyncMessage::IsMessageReplyTo(const Message& msg, int request_id) {
   if (!msg.is_reply())
     return false;
 
   return GetMessageId(msg) == request_id;
 }
 
-void* SyncMessage::GetDataIterator(const Message* msg) {
-  void* iter = const_cast<char*>(msg->payload());
-  UpdateIter(&iter, kSyncMessageHeaderSize);
-  return iter;
+PickleIterator SyncMessage::GetDataIterator(const Message* msg) {
+  PickleIterator iter(*msg);
+  if (!iter.SkipBytes(kSyncMessageHeaderSize))
+    return PickleIterator();
+  else
+    return iter;
 }
 
 int SyncMessage::GetMessageId(const Message& msg) {
   if (!msg.is_sync() && !msg.is_reply())
     return 0;
 
   SyncHeader header;
   if (!ReadSyncHeader(msg, &header))
     return 0;
 
@@ skipping 12 matching lines @@
   // use the same message id, but this time reply bit is set
   header.message_id = GetMessageId(*msg);
   WriteSyncHeader(reply, header);
 
   return reply;
 }
 
 bool SyncMessage::ReadSyncHeader(const Message& msg, SyncHeader* header) {
   DCHECK(msg.is_sync() || msg.is_reply());
 
-  void* iter = NULL;
+  PickleIterator iter(msg);
   bool result = msg.ReadInt(&iter, &header->message_id);
   if (!result) {
     NOTREACHED();
     return false;
   }
 
   return true;
 }
 
 bool SyncMessage::WriteSyncHeader(Message* msg, const SyncHeader& header) {
@@ skipping 10 matching lines @@
 
   return true;
 }
 
 
 bool MessageReplyDeserializer::SerializeOutputParameters(const Message& msg) {
   return SerializeOutputParameters(msg, SyncMessage::GetDataIterator(&msg));
 }
 
 }  // namespace IPC