Mojo: Report bindings validation errors via MojoNotifyBadMessage

mojo/public/cpp/bindings/lib/message_header_validator.h

Index: mojo/public/cpp/bindings/lib/message_header_validator.h
diff --git a/mojo/public/cpp/bindings/lib/message_header_validator.h b/mojo/public/cpp/bindings/lib/message_header_validator.h
index bccef1f772a4cfa6184dff3b924f497c23c90cdc..5ed1a9735fd1c91c225b463d66f59fa22a48b394 100644
--- a/mojo/public/cpp/bindings/lib/message_header_validator.h
+++ b/mojo/public/cpp/bindings/lib/message_header_validator.h
@@ -5,6 +5,8 @@
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_MESSAGE_HEADER_VALIDATOR_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_MESSAGE_HEADER_VALIDATOR_H_
 
+#include <string>
+
 #include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/bindings/message_filter.h"
 
@@ -14,8 +16,16 @@ namespace internal {
 class MessageHeaderValidator : public MessageFilter {
  public:
   explicit MessageHeaderValidator(MessageReceiver* sink = nullptr);
+  MessageHeaderValidator(MessageReceiver* sink, const std::string& debug_info);
+
+  void set_debug_info(const std::string& debug_info) {
+    debug_info_ = debug_info;
+  }
+
+  bool Accept(Message* message, Error* error) override;
 
-  bool Accept(Message* message) override;
+ private:
+  std::string debug_info_;
 };
 
 }  // namespace internal