Add better handle tracking, and optimize Connector::Accept.

mojo/public/bindings/lib/message.h

 // Copyright 2013 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 MOJO_PUBLIC_BINDINGS_LIB_MESSAGE_H_
 #define MOJO_PUBLIC_BINDINGS_LIB_MESSAGE_H_
 
 #include <vector>
 
 #include "mojo/public/system/core.h"
@@ skipping 10 matching lines @@
 
 struct MessageData {
   MessageHeader header;
   uint8_t payload[1];
 };
 MOJO_COMPILE_ASSERT(sizeof(MessageData) == 9, bad_sizeof_MessageData);
 
 #pragma pack(pop)
 
 // Message is a holder for the data and handles to be sent over a MessagePipe.
-// Message owns its data, but a consumer of Message is free to manipulate the
-// data member or replace it. If replacing, then be sure to use |malloc| to
-// allocate the memory.
+// Message owns its data and handles, but a consumer of Message is free to
+// manipulate the data and handles members.
 class Message {
  public:
   Message();
   ~Message();
 
   void Swap(Message* other);
 
-  MessageData* data;  // Heap-allocated.
+  MessageData* data;  // Heap-allocated using malloc.
   std::vector<Handle> handles;
 
  private:
   MOJO_DISALLOW_COPY_AND_ASSIGN(Message);
 };
 
 class MessageReceiver {
  public:
   // The receiver may mutate the given message or take ownership of its
   // |message->data| member by setting it to NULL.  Returns true if the message
   // was accepted and false otherwise, indicating that the message was invalid
   // or malformed.
   virtual bool Accept(Message* message) = 0;
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_BINDINGS_LIB_MESSAGE_H_