Change Dart_QualifiedTypeName to use VM code directly and not use the dart api function

runtime/vm/mirrors_api_impl.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_mirrors_api.h"
 
 #include "platform/assert.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
 #include "vm/dart_api_impl.h"
@@ skipping 24 matching lines @@
 }
 
 
 DART_EXPORT Dart_Handle Dart_QualifiedTypeName(Dart_Handle object) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
   const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(object));
   if (obj.IsType() || obj.IsClass()) {
     const Class& cls = (obj.IsType()) ?
         Class::Handle(Type::Cast(obj).type_class()) : Class::Cast(obj);
-    return Dart_NewStringFromCString(cls.ToCString());
+    const char* str = cls.ToCString();
+    if (str == NULL) {
+      RETURN_NULL_ERROR(str);
+    }
+    CHECK_CALLBACK_STATE(isolate);
+    return Api::NewHandle(isolate, String::New(str));
   } else {
     RETURN_TYPE_ERROR(isolate, object, Class/Type);
   }
 }
 
 
 // --- Function and Variable Reflection ---
 
 // Outside of the vm, we expose setter names with a trailing '='.
 static bool HasExternalSetterSuffix(const String& name) {
@@ skipping 310 matching lines @@
     RETURN_TYPE_ERROR(isolate, closure, Instance);
   }
 
   ASSERT(ClassFinalizer::AllClassesFinalized());
 
   RawFunction* rf = Closure::function(closure_obj);
   return Api::NewHandle(isolate, rf);
 }
 
 }  // namespace dart