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

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

Index: mojo/public/cpp/bindings/lib/binding_state.cc
diff --git a/mojo/public/cpp/bindings/lib/binding_state.cc b/mojo/public/cpp/bindings/lib/binding_state.cc
index 6d92f7239acf3d1b3ef17df8e78d7ab537e20e81..b63677e41714b86f5dd463e69b2f5839faf0aff6 100644
--- a/mojo/public/cpp/bindings/lib/binding_state.cc
+++ b/mojo/public/cpp/bindings/lib/binding_state.cc
@@ -40,6 +40,14 @@ void SimpleBindingState::Close() {
   DestroyRouter();
 }
 
+void SimpleBindingState::CloseWithReason(uint32_t custom_reason,
+                                         const std::string& description) {
+  if (router_)
+    router_->control_message_proxy()->SendDisconnectReason(custom_reason,
+                                                           description);
+  Close();
+}
+
 void SimpleBindingState::FlushForTesting() {
   router_->control_message_proxy()->FlushForTesting();
 }
@@ -65,20 +73,11 @@ void SimpleBindingState::BindInternal(
                                  has_sync_methods, std::move(runner),
                                  interface_version);
   router_->set_incoming_receiver(stub);
-  router_->set_connection_error_handler(base::Bind(
-      &SimpleBindingState::RunConnectionErrorHandler, base::Unretained(this)));
 }
 
 void SimpleBindingState::DestroyRouter() {
-  router_->set_connection_error_handler(base::Closure());
   delete router_;
   router_ = nullptr;
-  connection_error_handler_.Reset();
-}
-
-void SimpleBindingState::RunConnectionErrorHandler() {
-  if (!connection_error_handler_.is_null())
-    connection_error_handler_.Run();
 }
 
 // -----------------------------------------------------------------------------
@@ -118,7 +117,14 @@ void MultiplexedBindingState::Close() {
   endpoint_client_.reset();
   router_->CloseMessagePipe();
   router_ = nullptr;
-  connection_error_handler_.Reset();
+}
+
+void MultiplexedBindingState::CloseWithReason(uint32_t custom_reason,
+                                              const std::string& description) {
+  if (endpoint_client_)
+    endpoint_client_->control_message_proxy()->SendDisconnectReason(
+        custom_reason, description);
+  Close();
 }
 
 void MultiplexedBindingState::FlushForTesting() {
@@ -147,15 +153,6 @@ void MultiplexedBindingState::BindInternal(
       router_->CreateLocalEndpointHandle(kMasterInterfaceId), stub,
       std::move(request_validator), has_sync_methods, std::move(runner),
       interface_version));
-
-  endpoint_client_->set_connection_error_handler(
-      base::Bind(&MultiplexedBindingState::RunConnectionErrorHandler,
-                 base::Unretained(this)));
-}
-
-void MultiplexedBindingState::RunConnectionErrorHandler() {
-  if (!connection_error_handler_.is_null())
-    connection_error_handler_.Run();
 }
 
 }  // namesapce internal