Address comments I missed on a previous CL

I accidentally missed some comments on
android-review.googlesource.com/c/305518 when I submitted it. This
addresses those comments.

Test: mma -j40 test-art-host
Change-Id: Icd8ff65dee1730d10489f25e75bddbd455c68413
diff --git a/runtime/art_method.cc b/runtime/art_method.cc
index eeece90..ce1cf23 100644
--- a/runtime/art_method.cc
+++ b/runtime/art_method.cc
@@ -68,7 +68,8 @@
   DCHECK(ext->GetObsoleteDexCaches() != nullptr);
   int32_t len = obsolete_methods->GetLength();
   DCHECK_EQ(len, ext->GetObsoleteDexCaches()->GetLength());
-  // TODO I think this is fine since images should never have obsolete methods in them.
+  // Using kRuntimePointerSize (instead of using the image's pointer size) is fine since images
+  // should never have obsolete methods in them so they should always be the same.
   PointerSize pointer_size = kRuntimePointerSize;
   DCHECK_EQ(kRuntimePointerSize, Runtime::Current()->GetClassLinker()->GetImagePointerSize());
   for (int32_t i = 0; i < len; i++) {