Refactorings only: More uses of "To" template and comment fixes.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 3b0443cdb3b99f37d15e30efc78877078472c49c..1b5ce957bf16699f147b934fe8883c3a5ced2379 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2506,8 +2506,8 @@ class DescriptorArray: public FixedArray {
   MUST_USE_RESULT MaybeObject* CopyInsert(Descriptor* descriptor,
                                           TransitionFlag transition_flag);
 
-  // Remove all transitions.  Return  a copy of the array with all transitions
-  // removed, or a Failure object if the new array could not be allocated.
+  // Return a copy of the array with all transitions and null descriptors
+  // removed. Return a Failure object in case of an allocation failure.
   MUST_USE_RESULT MaybeObject* RemoveTransitions();
 
   // Sort the instance descriptors by the hash codes of their keys.