[cleanup] Remove stale TODOs

Change-Id: Ibfbb306d52092bc9e9564d1e1b2d1cb7f7edfbb9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2844662
Auto-Submit: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74146}

src/heap/heap.cc

@@ -3541,8 +3541,6 @@ void Heap::ActivateMemoryReducerIfNeeded() {
 }
 
 void Heap::ReduceNewSpaceSize() {
-  // TODO(ulan): Unify this constant with the similar constant in
-  // GCIdleTimeHandler once the change is merged to 4.5.
   static const size_t kLowAllocationThroughput = 1000;
   const double allocation_throughput =
       tracer()->CurrentAllocationThroughputInBytesPerMillisecond();

test/cctest/heap/test-memory-measurement.cc

@@ -57,8 +57,6 @@ TEST(NativeContextInferrerJSObject) {
   Handle<HeapObject> function = Handle<HeapObject>::cast(object);
   NativeContextInferrer inferrer;
   Address inferred_context = 0;
-  // TODO(ulan): Enable this test once we have more precise native
-  // context inference.
   CHECK(inferrer.Infer(isolate, function->map(), *function, &inferred_context));
   CHECK_EQ(native_context->ptr(), inferred_context);
 }