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

ipc/ipc_message.h

 // 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_IPC_MESSAGE_H_
 #define IPC_IPC_MESSAGE_H_
 #pragma once
 
 #include <string>
 
@@ skipping 131 matching lines @@
   }
 
   void set_routing_id(int32 new_id) {
     header()->routing = new_id;
   }
 
   uint32 flags() const {
     return header()->flags;
   }
 
+  // Sets all the given header values. The message should be empty at this
+  // call.
+  void SetHeaderValues(int32 routing, uint32 type, uint32 flags);
+
   template<class T, class S>
   static bool Dispatch(const Message* msg, T* obj, S* sender,
                        void (T::*func)()) {
     (obj->*func)();
     return true;
   }
 
   template<class T, class S>
   static bool Dispatch(const Message* msg, T* obj, S* sender,
                        void (T::*func)() const) {
@@ skipping 22 matching lines @@
   // Find the end of the message data that starts at range_start.  Returns NULL
   // if the entire message is not found in the given data range.
   static const char* FindNext(const char* range_start, const char* range_end) {
     return Pickle::FindNext(sizeof(Header), range_start, range_end);
   }
 
 #if defined(OS_POSIX)
   // On POSIX, a message supports reading / writing FileDescriptor objects.
   // This is used to pass a file descriptor to the peer of an IPC channel.
 
-  // Add a descriptor to the end of the set. Returns false iff the set is full.
+  // Add a descriptor to the end of the set. Returns false if the set is full.
   bool WriteFileDescriptor(const base::FileDescriptor& descriptor);
+
   // Get a file descriptor from the message. Returns false on error.
   //   iter: a Pickle iterator to the current location in the message.
   bool ReadFileDescriptor(PickleIterator* iter,
                           base::FileDescriptor* descriptor) const;
+
+  // Returns true if there are any file descriptors in this message.
+  bool HasFileDescriptors() const;
 #endif
 
 #ifdef IPC_MESSAGE_LOG_ENABLED
   // Adds the outgoing time from Time::Now() at the end of the message and sets
   // a bit to indicate that it's been added.
   void set_sent_time(int64 time);
   int64 sent_time() const;
 
   void set_received_time(int64 time) const;
   int64 received_time() const { return received_time_; }
@@ skipping 69 matching lines @@
   MSG_ROUTING_NONE = -2,
 
   // indicates a general message not sent to a particular tab.
   MSG_ROUTING_CONTROL = kint32max,
 };
 
 #define IPC_REPLY_ID 0xFFFFFFF0  // Special message id for replies
 #define IPC_LOGGING_ID 0xFFFFFFF1  // Special message id for logging
 
 #endif  // IPC_IPC_MESSAGE_H_