Revert "ART: Fix JDWP GetClassLoader command"

This reverts commit 40144cc022d321e2ec28d7fac2f5a24ba6714aff.

The implementation should not DCHECK.

Bug: 26349019
Change-Id: I9238ee0b05f8a150f55773e78301ded9e8b38334
diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index f009fe6..e0211f5 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -730,8 +730,7 @@
   if (o == nullptr) {
     return JDWP::ERR_INVALID_OBJECT;
   }
-  DCHECK(o->IsClass());
-  expandBufAddObjectId(pReply, gRegistry->Add(o->AsClass()->GetClassLoader()));
+  expandBufAddObjectId(pReply, gRegistry->Add(o->GetClass()->GetClassLoader()));
   return JDWP::ERR_NONE;
 }