Mojo: Add NotifyBadMessage API

mojo/public/c/system/message_pipe.h

 // Copyright 2014 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.
 
 // This file contains types/constants and functions specific to message pipes.
 //
 // Note: This header should be compilable as C.
 
 #ifndef MOJO_PUBLIC_C_SYSTEM_MESSAGE_PIPE_H_
 #define MOJO_PUBLIC_C_SYSTEM_MESSAGE_PIPE_H_
@@ skipping 295 matching lines @@
 //
 // Returns:
 //   |MOJO_RESULT_OK| if |message| is a valid message object. |*buffer| will
 //       be updated to point to mutable message bytes.
 //   |MOJO_RESULT_INVALID_ARGUMENT| if |message| is not a valid message object.
 //
 // NOTE: A returned buffer address is always guaranteed to be 8-byte aligned.
 MOJO_SYSTEM_EXPORT MojoResult MojoGetMessageBuffer(MojoMessageHandle message,
                                                    void** buffer);  // Out
 
+// Notifies the system that a bad message was received on a message pipe,
+// according to whatever criteria the caller chooses. This ultimately tries to
+// notify the embedder about the bad message, and the embedder may enforce some
+// policy for dealing with the source of the message (e.g. close the pipe,
+// terminate, a process, etc.) The embedder may not be notified if the calling
+// process has lost its connection to the source process.
+//
+// |message|: The message to report as bad. This must have come from a call to
+//     |MojoReadMessageNew()|.
+// |error|: An error string which may provide the embedder with context when
+//     notified of this error.
+// |error_num_bytes|: The length of |error| in bytes.
+//
+// Returns:
+//   |MOJO_RESULT_OK| if successful.
+//   |MOJO_RESULT_INVALID_ARGUMENT| if |message| is not a valid message.
+MOJO_SYSTEM_EXPORT MojoResult
+MojoNotifyBadMessage(MojoMessageHandle message,
+                     const char* error,
+                     size_t error_num_bytes);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // MOJO_PUBLIC_C_SYSTEM_MESSAGE_PIPE_H_