Revert "Add read barriers for the roots in the verifier."

This reverts commit 7da9586b559290e1c16207c6513ffe485de61655.

Bug: 17398101

Change-Id: I1d6110fdf0d3a3c9241c8e7e7f4b85a298f9dd8e
diff --git a/runtime/verifier/method_verifier-inl.h b/runtime/verifier/method_verifier-inl.h
index 0f9aeb5..2d9fd53 100644
--- a/runtime/verifier/method_verifier-inl.h
+++ b/runtime/verifier/method_verifier-inl.h
@@ -66,9 +66,9 @@
   return !failure_messages_.empty();
 }
 
-inline RegType& MethodVerifier::ResolveCheckedClass(uint32_t class_idx) {
+inline const RegType& MethodVerifier::ResolveCheckedClass(uint32_t class_idx) {
   DCHECK(!HasFailures());
-  RegType& result = ResolveClassAndCheckAccess(class_idx);
+  const RegType& result = ResolveClassAndCheckAccess(class_idx);
   DCHECK(!HasFailures());
   return result;
 }