CPP bindings: DCHECK when a Callback is destructed without being invoked

mojo/public/cpp/bindings/tests/router_unittest.cc

Index: mojo/public/cpp/bindings/tests/router_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/router_unittest.cc b/mojo/public/cpp/bindings/tests/router_unittest.cc
index ed3792f9c4387c483bdfe431f423d77dad79d1de..d3d8ccb8eae93327ab55e1a0f2a7f96db69d21c7 100644
--- a/mojo/public/cpp/bindings/tests/router_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/router_unittest.cc
@@ -47,19 +47,20 @@ class MessageAccumulator : public MessageReceiver {
   internal::MessageQueue* queue_;
 };
 
-class ResponseGenerator : public MessageReceiverWithResponder {
+class ResponseGenerator : public MessageReceiverWithResponderStatus {
  public:
   ResponseGenerator() {}
 
   bool Accept(Message* message) override { return false; }
 
   bool AcceptWithResponder(Message* message,
-                           MessageReceiver* responder) override {
+                           MessageReceiverWithStatus* responder) override {
     EXPECT_TRUE(message->has_flag(internal::kMessageExpectsResponse));
 
     bool result = SendResponse(
         message->name(), message->request_id(),
         reinterpret_cast<const char*>(message->payload()), responder);
+    EXPECT_TRUE(responder->IsValid());
     delete responder;
     return result;
   }
@@ -84,7 +85,7 @@ class LazyResponseGenerator : public ResponseGenerator {
   ~LazyResponseGenerator() override { delete responder_; }
 
   bool AcceptWithResponder(Message* message,
-                           MessageReceiver* responder) override {
+                           MessageReceiverWithStatus* responder) override {
     name_ = message->name();
     request_id_ = message->request_id();
     request_string_ =
@@ -95,6 +96,8 @@ class LazyResponseGenerator : public ResponseGenerator {
 
   bool has_responder() const { return !!responder_; }
 
+  bool responder_is_valid() const { return responder_->IsValid(); }
+
   // Send the response and delete the responder.
   void CompleteWithResponse() { Complete(true); }
 
@@ -112,7 +115,7 @@ class LazyResponseGenerator : public ResponseGenerator {
     responder_ = nullptr;
   }
 
-  MessageReceiver* responder_;
+  MessageReceiverWithStatus* responder_;
   uint32_t name_;
   uint64_t request_id_;
   std::string request_string_;
@@ -261,6 +264,7 @@ TEST_F(RouterTest, LazyResponses) {
   EXPECT_TRUE(message_queue.IsEmpty());
 
   // Send the response.
+  EXPECT_TRUE(generator.responder_is_valid());
   generator.CompleteWithResponse();
   PumpMessages();
 
@@ -283,6 +287,7 @@ TEST_F(RouterTest, LazyResponses) {
   EXPECT_TRUE(message_queue.IsEmpty());
 
   // Send the second response.
+  EXPECT_TRUE(generator.responder_is_valid());
   generator.CompleteWithResponse();
   PumpMessages();
 
@@ -358,6 +363,7 @@ TEST_F(RouterTest, LateResponse) {
     EXPECT_TRUE(generator.has_responder());
   }
 
+  EXPECT_FALSE(generator.responder_is_valid());
   generator.CompleteWithResponse();  // This should end up doing nothing.
 }