Mojo C++ bindings: support disconnect with a reason.

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

Index: mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
diff --git a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
index 30a3c428e92ccbe21bdadbce7a6480417fa9546b..839978dbbaace1eb6efe4aa422b2b75c9c02a9a6 100644
--- a/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
+++ b/mojo/public/cpp/bindings/lib/associated_interface_ptr_state.h
@@ -9,6 +9,7 @@
 
 #include <algorithm>  // For |std::swap()|.
 #include <memory>
+#include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ -20,6 +21,7 @@
 #include "mojo/public/cpp/bindings/associated_group.h"
 #include "mojo/public/cpp/bindings/associated_group_controller.h"
 #include "mojo/public/cpp/bindings/associated_interface_ptr_info.h"
+#include "mojo/public/cpp/bindings/connection_error_callback.h"
 #include "mojo/public/cpp/bindings/interface_endpoint_client.h"
 #include "mojo/public/cpp/bindings/interface_id.h"
 #include "mojo/public/cpp/bindings/lib/control_message_handler.h"
@@ -72,6 +74,12 @@ class AssociatedInterfacePtrState {
     endpoint_client_->control_message_proxy()->FlushForTesting();
   }
 
+  void SendDisconnectReason(uint32_t custom_reason,
+                            const std::string& description) {
+    endpoint_client_->control_message_proxy()->SendDisconnectReason(
+        custom_reason, description);
+  }
+
   void Swap(AssociatedInterfacePtrState* other) {
     using std::swap;
     swap(other->endpoint_client_, endpoint_client_);
@@ -118,6 +126,12 @@ class AssociatedInterfacePtrState {
     endpoint_client_->set_connection_error_handler(error_handler);
   }
 
+  void set_connection_error_with_reason_handler(
+      const ConnectionErrorWithReasonCallback& error_handler) {
+    DCHECK(endpoint_client_);
+    endpoint_client_->set_connection_error_with_reason_handler(error_handler);
+  }
+
   // Returns true if bound and awaiting a response to a message.
   bool has_pending_callbacks() const {
     return endpoint_client_ && endpoint_client_->has_pending_responders();