cppgc: young-gen: Join concurrent marking for young GC cycles

Bug: chromium:1029379
Change-Id: I34e988c0e14441afe821a35505c4ce3f1eee8fc4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3584118Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79974}

src/heap/cppgc-js/cpp-heap.cc

@@ -698,7 +698,10 @@ void CppHeap::RunMinorGC(StackState stack_state) {
   StartTracing();
   // TODO(chromium:1029379): Should be safe to run without stack.
   EnterFinalPause(cppgc::EmbedderStackState::kMayContainHeapPointers);
-  AdvanceTracing(std::numeric_limits<double>::infinity());
+  CHECK(AdvanceTracing(std::numeric_limits<double>::infinity()));
+  if (FinishConcurrentMarkingIfNeeded()) {
+    CHECK(AdvanceTracing(std::numeric_limits<double>::infinity()));
+  }
   TraceEpilogue();
 }