Mojo: Add NotifyBadMessage API

mojo/public/cpp/system/message.h

Index: mojo/public/cpp/system/message.h
diff --git a/mojo/public/cpp/system/message.h b/mojo/public/cpp/system/message.h
index f9002e4c51aa5884e2be91ad94be0d360d0e3bb5..d4406ee808e86aed738b59b4a180cc66e5f3c70b 100644
--- a/mojo/public/cpp/system/message.h
+++ b/mojo/public/cpp/system/message.h
@@ -8,6 +8,7 @@
 #include <limits>
 
 #include "base/macros.h"
+#include "base/strings/string_piece.h"
 #include "mojo/public/c/system/message_pipe.h"
 #include "mojo/public/cpp/system/handle.h"
 
@@ -71,6 +72,12 @@ inline MojoResult GetMessageBuffer(MessageHandle message, void** buffer) {
   return MojoGetMessageBuffer(message.value(), buffer);
 }
 
+inline MojoResult NotifyBadMessage(MessageHandle message,
+                                   const base::StringPiece& error) {
+  DCHECK(message.is_valid());
+  return MojoNotifyBadMessage(message.value(), error.data(), error.size());
+}
+
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_SYSTEM_MESSAGE_H_