Change indirect reference table to use ObjPtr

Bug: 31113334

Test: test-art-host

Change-Id: I340fdf430897ebd790ea4e35f94bcee776e98445
diff --git a/runtime/jni_env_ext.h b/runtime/jni_env_ext.h
index 79dfb0d..121f848 100644
--- a/runtime/jni_env_ext.h
+++ b/runtime/jni_env_ext.h
@@ -47,8 +47,7 @@
   void PopFrame() REQUIRES_SHARED(Locks::mutator_lock_);
 
   template<typename T>
-  T AddLocalReference(mirror::Object* obj)
-      REQUIRES_SHARED(Locks::mutator_lock_);
+  T AddLocalReference(ObjPtr<mirror::Object> obj) REQUIRES_SHARED(Locks::mutator_lock_);
 
   static Offset SegmentStateOffset(size_t pointer_size);
   static Offset LocalRefCookieOffset(size_t pointer_size);