Revert change 6302 until the compiler warning is addressed.

vm/stack_frame_test.cc

Index: vm/stack_frame_test.cc
===================================================================
--- vm/stack_frame_test.cc	(revision 6302)
+++ vm/stack_frame_test.cc	(working copy)
@@ -96,8 +96,6 @@
       if (function.IsNull()) {
         FATAL("StackFrame_validateFrame fails, invalid dart frame.\n");
       }
-      const Code& code = Code::Handle(frame->LookupDartCode());
-      EXPECT(code.raw() == function.unoptimized_code());
       const char* name = function.ToFullyQualifiedCString();
       // Currently all unit tests are loaded as being part of dart:core-lib.
       Isolate* isolate = Isolate::Current();