Mojo: Add NotifyBadMessage API

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

Index: mojo/public/cpp/bindings/lib/interface_endpoint_client.h
diff --git a/mojo/public/cpp/bindings/lib/interface_endpoint_client.h b/mojo/public/cpp/bindings/lib/interface_endpoint_client.h
index 3f820db3c30c66b179e6b2203478f66bb0b19509..f1de4c76012f31b8bf785f1e1ef7768d365c8970 100644
--- a/mojo/public/cpp/bindings/lib/interface_endpoint_client.h
+++ b/mojo/public/cpp/bindings/lib/interface_endpoint_client.h
@@ -67,6 +67,11 @@ class InterfaceEndpointClient : public MessageReceiverWithResponder {
   AssociatedGroup* associated_group();
   uint32_t interface_id() const;
 
+  void set_interface_name(const std::string& name) {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    interface_name_ = name;
+  }
+
   // After this call the object is in an invalid state and shouldn't be reused.
   ScopedInterfaceEndpointHandle PassHandle();
 
@@ -142,6 +147,10 @@ class InterfaceEndpointClient : public MessageReceiverWithResponder {
   Closure error_handler_;
   bool encountered_error_;
 
+  // The name of the interface which is bound by this client. Used only for
+  // debugging purposes.
+  std::string interface_name_;
+
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   base::ThreadChecker thread_checker_;