Make the serialization of IPC::Messages inside other IPC::Messages independent

ipc/ipc_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 "ipc/ipc_message.h"
 
 #include "base/logging.h"
 #include "build/build_config.h"
 
 #if defined(OS_POSIX)
@@ skipping 49 matching lines @@
 }
 
 Message& Message::operator=(const Message& other) {
   *static_cast<Pickle*>(this) = other;
 #if defined(OS_POSIX)
   file_descriptor_set_ = other.file_descriptor_set_;
 #endif
   return *this;
 }
 
+void Message::SetHeaderValues(int32 routing, uint32 type, uint32 flags) {
+  // This should only be called when the message is already empty.
+  DCHECK(payload_size() == 0);
+
+  header()->routing = routing;
+  header()->type = type;
+  header()->flags = flags;
+}
+
 #ifdef IPC_MESSAGE_LOG_ENABLED
 void Message::set_sent_time(int64 time) {
   DCHECK((header()->flags & HAS_SENT_TIME_BIT) == 0);
   header()->flags |= HAS_SENT_TIME_BIT;
   WriteInt64(time);
 }
 
 int64 Message::sent_time() const {
   if ((header()->flags & HAS_SENT_TIME_BIT) == 0)
     return 0;
@@ skipping 29 matching lines @@
   FileDescriptorSet* file_descriptor_set = file_descriptor_set_.get();
   if (!file_descriptor_set)
     return false;
 
   descriptor->fd = file_descriptor_set->GetDescriptorAt(descriptor_index);
   descriptor->auto_close = true;
 
   return descriptor->fd >= 0;
 }
 
+bool Message::HasFileDescriptors() const {
+  return file_descriptor_set_.get() && !file_descriptor_set_->empty();
+}
+
 void Message::EnsureFileDescriptorSet() {
   if (file_descriptor_set_.get() == NULL)
     file_descriptor_set_ = new FileDescriptorSet;
 }
 
 #endif
 
 }  // namespace IPC