Mojo: Add NotifyBadMessage API

mojo/public/cpp/bindings/lib/interface_endpoint_client.cc

Index: mojo/public/cpp/bindings/lib/interface_endpoint_client.cc
diff --git a/mojo/public/cpp/bindings/lib/interface_endpoint_client.cc b/mojo/public/cpp/bindings/lib/interface_endpoint_client.cc
index 9e32c5af239b3ff45f5d22a64d0a70165f20d5b1..38e82755fcf756eb9122e629af1c25e4cb786e3e 100644
--- a/mojo/public/cpp/bindings/lib/interface_endpoint_client.cc
+++ b/mojo/public/cpp/bindings/lib/interface_endpoint_client.cc
@@ -256,7 +256,12 @@ bool InterfaceEndpointClient::AcceptWithResponder(Message* message,
 bool InterfaceEndpointClient::HandleIncomingMessage(Message* message) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  return payload_validator_->Accept(message);
+  if (!payload_validator_->Accept(message)) {
+    message->NotifyBadMessage(interface_name_);

[yzshen1, 2016/06/11 00:10:59]

If you think it is useful, we can also record the message type (which is the
ordinal number of the method).

+    return false;
+  }
+
+  return true;
 }
 
 void InterfaceEndpointClient::NotifyError() {