Fis OSS QUICHE build.

`absl::AnyInvocable` supports `operator==` against `std::nullptr_t`, but not
another `absl::AnyInvocable`. A bare `nullptr` in `EXPECT_CALL` constructs an
`absl::AnyInvocable` for `testing::Eq` and fails to compile; `testing::IsNull()`
compares directly against `nullptr`.

PiperOrigin-RevId: 963702671

quiche/quic/moqt/moqt_publish_namespace_stream_test.cc

diff --git a/quiche/quic/moqt/moqt_publish_namespace_stream_test.cc b/quiche/quic/moqt/moqt_publish_namespace_stream_test.cc
index f244f80..f7153cd 100644
--- a/quiche/quic/moqt/moqt_publish_namespace_stream_test.cc
+++ b/quiche/quic/moqt/moqt_publish_namespace_stream_test.cc
@@ -30,6 +30,7 @@
 namespace moqt::test {
 
 using ::testing::_;
+using ::testing::IsNull;
 using ::testing::Return;
 using ::testing::StrictMock;
 
@@ -275,7 +276,7 @@
   // Since it was published (published_ = true), Detach() should call
   // remove_callback_ and application_(*prefix_, nullptr, nullptr).
   EXPECT_CALL(remove_callback_, Call(TrackNamespace({"foo"})));
-  EXPECT_CALL(application_, Call(TrackNamespace({"foo"}), nullptr, nullptr));
+  EXPECT_CALL(application_, Call(TrackNamespace({"foo"}), IsNull(), IsNull()));
 
   response_stream = nullptr;  // Destroys response_stream, triggering Detach().
 }

quiche/quic/moqt/moqt_session_test.cc

diff --git a/quiche/quic/moqt/moqt_session_test.cc b/quiche/quic/moqt/moqt_session_test.cc
index bd81199..cbd80cc 100644
--- a/quiche/quic/moqt/moqt_session_test.cc
+++ b/quiche/quic/moqt/moqt_session_test.cc
@@ -59,6 +59,7 @@
 namespace {
 
 using ::testing::_;
+using ::testing::IsNull;
 using ::testing::Optional;
 using ::testing::Return;
 using ::testing::StrictMock;
@@ -1047,7 +1048,7 @@
                      _));
   bidi_wrapper_->ReceiveMessage(publish_namespace);
   EXPECT_CALL(session_callbacks_.incoming_publish_namespace_callback,
-              Call(track_namespace, nullptr, nullptr));
+              Call(track_namespace, IsNull(), IsNull()));
   bidi_wrapper_->stream().OnResetStreamReceived(kResetCodeCancelled);
 }
 
@@ -1077,7 +1078,7 @@
                      _));
   bidi_wrapper_->ReceiveMessage(publish_namespace);
   EXPECT_CALL(session_callbacks_.incoming_publish_namespace_callback,
-              Call(track_namespace, nullptr, nullptr));
+              Call(track_namespace, IsNull(), IsNull()));
   EXPECT_TRUE(
       session_.PublishNamespaceCancel(track_namespace, kResetCodeCancelled));
   // State is gone.
@@ -2636,12 +2637,12 @@
 
   // Revoke "bar"
   EXPECT_CALL(session_callbacks_.incoming_publish_namespace_callback,
-              Call(TrackNamespace{"bar"}, nullptr, nullptr));
+              Call(TrackNamespace{"bar"}, IsNull(), IsNull()));
   bidi_wrapper_2->stream().OnResetStreamReceived(kResetCodeCancelled);
 
   // Destroying the session should revoke "foo".
   EXPECT_CALL(session_callbacks_.incoming_publish_namespace_callback,
-              Call(TrackNamespace{"foo"}, nullptr, nullptr));
+              Call(TrackNamespace{"foo"}, IsNull(), IsNull()));
   // Test teardown will destroy session_, triggering removal of "foo".
 }