ObjPtr<>-ify mirror::ObjectArray.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 31113334
Change-Id: I611b3e49d3feed306f6cd35d2b662a1e727e24c6
diff --git a/runtime/native/java_lang_reflect_Method.cc b/runtime/native/java_lang_reflect_Method.cc
index c65541d..4525157 100644
--- a/runtime/native/java_lang_reflect_Method.cc
+++ b/runtime/native/java_lang_reflect_Method.cc
@@ -59,7 +59,7 @@
       ++i;
     }
     CHECK_NE(throws_index, -1);
-    mirror::ObjectArray<mirror::Class>* declared_exceptions =
+    ObjPtr<mirror::ObjectArray<mirror::Class>> declared_exceptions =
         klass->GetProxyThrows()->Get(throws_index);
     return soa.AddLocalReference<jobjectArray>(declared_exceptions->Clone(soa.Self()));
   } else {