Update missed comment.

Change-Id: I45b1e96c18d7117669c6a59a8431c9ab441a8fee

1 files changed, 3 insertions, 2 deletions

diff --git a/runtime/gc/heap_test.cc b/runtime/gc/heap_test.cc
index 57358e6ef1..42ba911062 100644
--- a/runtime/gc/heap_test.cc
+++ b/runtime/gc/heap_test.cc
@@ -120,8 +120,9 @@ TEST_F(HeapTest, GCMetrics) {
       Handle<mirror::String> string [[maybe_unused]] (
           hs.NewHandle(mirror::String::AllocFromModifiedUtf8(soa.Self(), "test")));
     }
-    // Do one GC while the temporary objects cannot be collected. This GC will age the objects,and
-    // ensure that the GC at line 127 does scan the objects.
+    // Do one GC while the temporary objects are reachable, forcing the GC to scan something.
+    // The subsequent GC at line 127 may not scan anything but will certainly free some bytes.
+    // Together the two GCs ensure success of the test.
     heap->CollectGarbage(/* clear_soft_references= */ false);
   }
   heap->CollectGarbage(/* clear_soft_references= */ false);