Mojo: Report bindings validation errors via MojoNotifyBadMessage

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

Index: mojo/public/cpp/bindings/lib/control_message_proxy.cc
diff --git a/mojo/public/cpp/bindings/lib/control_message_proxy.cc b/mojo/public/cpp/bindings/lib/control_message_proxy.cc
index 6189e6973e792f691b9a94fb8cdc7ec329062273..92b8cb8301727fadba22a3c745b42212ddcf6009 100644
--- a/mojo/public/cpp/bindings/lib/control_message_proxy.cc
+++ b/mojo/public/cpp/bindings/lib/control_message_proxy.cc
@@ -25,14 +25,14 @@ class RunResponseForwardToCallback : public MessageReceiver {
  public:
   RunResponseForwardToCallback(const RunCallback& callback)
       : callback_(callback) {}
-  bool Accept(Message* message) override;
+  bool Accept(Message* message, Error* error) override;
 
  private:
   RunCallback callback_;
   DISALLOW_COPY_AND_ASSIGN(RunResponseForwardToCallback);
 };
 
-bool RunResponseForwardToCallback::Accept(Message* message) {
+bool RunResponseForwardToCallback::Accept(Message* message, Error* error) {
   RunResponseMessageParams_Data* params =
       reinterpret_cast<RunResponseMessageParams_Data*>(
           message->mutable_payload());
@@ -63,7 +63,8 @@ void SendRunMessage(MessageReceiverWithResponder* receiver,
                                  context);
   params->EncodePointers();
   MessageReceiver* responder = new RunResponseForwardToCallback(callback);
-  if (!receiver->AcceptWithResponder(builder.message(), responder))
+  Error send_error;
+  if (!receiver->AcceptWithResponder(builder.message(), responder, &send_error))
     delete responder;
 }
 
@@ -83,7 +84,8 @@ void SendRunOrClosePipeMessage(MessageReceiverWithResponder* receiver,
   Serialize<RunOrClosePipeMessageParamsPtr>(params_ptr, builder.buffer(),
                                             &params, context);
   params->EncodePointers();
-  bool ok = receiver->Accept(builder.message());
+  Error send_error;
+  bool ok = receiver->Accept(builder.message(), &send_error);
   ALLOW_UNUSED_LOCAL(ok);
 }