Propagate the read barrier option to Class::VisitNativeRoots.

Propagate the read barrier option from Object::VisitReferences to
Class::VisitNativeRoots.

This is a step toward the GC thread avoiding graying objects (and
reducing dirty pages) in the immune spaces.

Bug: 12687968

Change-Id: I29c4126a4ad4c40e63a934e62451fb3fb36aad43
diff --git a/runtime/mirror/class.h b/runtime/mirror/class.h
index 8c20fa6..5235a3e 100644
--- a/runtime/mirror/class.h
+++ b/runtime/mirror/class.h
@@ -1156,7 +1156,7 @@
 
   // Visit native roots visits roots which are keyed off the native pointers such as ArtFields and
   // ArtMethods.
-  template<class Visitor>
+  template<ReadBarrierOption kReadBarrierOption = kWithReadBarrier, class Visitor>
   void VisitNativeRoots(Visitor& visitor, size_t pointer_size)
       SHARED_REQUIRES(Locks::mutator_lock_);