resolve comments

src/cpp/client/insecure_credentials.cc

@@ -52,7 +52,8 @@ class InsecureCredentialsImpl GRPC_FINAL : public Credentials {
         target, grpc_channel_create(target.c_str(), &channel_args)));
   }
 
-  bool ApplyToCall(grpc_call* call) GRPC_OVERRIDE { return true; }
+  // InsecureCredentials should not be applied to a call.
+  bool ApplyToCall(grpc_call* call) GRPC_OVERRIDE { return false; }
 
   SecureCredentials* AsSecureCredentials() GRPC_OVERRIDE { return nullptr; }
 };

test/cpp/end2end/end2end_test.cc

@@ -614,8 +614,8 @@ TEST_F(End2endTest, InsecurePerCallCredentials) {
   grpc::string msg("Hello");
 
   Status s = stub_->Echo(&context, request, &response);
-  EXPECT_EQ(request.message(), response.message());
+  EXPECT_EQ(StatusCode::CANCELLED, s.code());
-  EXPECT_TRUE(s.IsOk());
+  EXPECT_EQ("Failed to set credentials to rpc.", s.details());
 }
 
 TEST_F(End2endTest, OverridePerCallCredentials) {
@@ -623,7 +623,7 @@ TEST_F(End2endTest, OverridePerCallCredentials) {
   EchoRequest request;
   EchoResponse response;
   ClientContext context;
-  std::shared_ptr<Credentials> creds1 = InsecureCredentials();
+  std::shared_ptr<Credentials> creds1 = SslCredentials(SslCredentialsOptions());
   context.set_credentials(creds1);
   std::shared_ptr<Credentials> creds2 =
       IAMCredentials("fake_token", "fake_selector");