Fix a variety of service protocol bugs.

runtime/vm/object.cc

 // Copyright (c) 2012, 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 "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 1649 matching lines @@
   const char* vm_type = JSONType();
   bool same_type = (strcmp(protocol_type, vm_type) == 0);
   if (ref) {
     jsobj->AddPropertyF("type", "@%s", protocol_type);
   } else {
     jsobj->AddProperty("type", protocol_type);
   }
   if (!same_type) {
     jsobj->AddProperty("_vmType", vm_type);
   }
-  if (!ref || IsInstance()) {
+  if (!ref || IsInstance() || IsNull()) {
     // TODO(turnidge): Provide the type arguments here too?
     const Class& cls = Class::Handle(this->clazz());
     jsobj->AddProperty("class", cls);
   }
   if (!ref) {
     if (raw()->IsHeapObject()) {
       jsobj->AddProperty("size", raw()->Size());
     } else {
       jsobj->AddProperty("size", (intptr_t)0);
     }
@@ skipping 19754 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart