Provide a logical view of VM-internal maps in Observatory.

runtime/observatory/lib/src/service/object.dart

 // Copyright (c) 2014, 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.
 
 part of service;
 
 /// An RpcException represents an exceptional event that happened
 /// while invoking an rpc.
 abstract class RpcException implements Exception {
   RpcException(this.message);
@@ skipping 1771 matching lines @@
 class Instance extends ServiceObject {
   @observable String kind;
   @observable Class clazz;
   @observable int size;
   @observable int retainedSize;
   @observable String valueAsString;  // If primitive.
   @observable bool valueAsStringIsTruncated;
   @observable ServiceFunction function;  // If a closure.
   @observable Context context;  // If a closure.
   @observable String name;  // If a Type.
-  @observable int length; // If a List.
+  @observable int length; // If a List or Map.
 
   @observable var typeClass;
   @observable var fields;
   @observable var nativeFields;
-  @observable var elements;
+  @observable var elements;  // If a List.
+  @observable var associations;  // If a Map.
   @observable var referent;  // If a MirrorReference.
   @observable Instance key;  // If a WeakProperty.
   @observable Instance value;  // If a WeakProperty.
 
   bool get isAbstractType {
     return (kind == 'Type' || kind == 'TypeRef' ||
             kind == 'TypeParameter' || kind == 'BoundedType');
   }
   bool get isNull => kind == 'Null';
   bool get isBool => kind == 'Bool';
@@ skipping 27 matching lines @@
     name = map['name'];
     length = map['length'];
 
     if (mapIsRef) {
       return;
     }
 
     nativeFields = map['_nativeFields'];
     fields = map['fields'];
     elements = map['elements'];
+    associations = map['associations'];
     typeClass = map['typeClass'];
     referent = map['mirrorReferent'];
     key = map['propertyKey'];
     value = map['propertyValue'];
 
     // We are fully loaded.
     _loaded = true;
   }
 
   String get shortName {
@@ skipping 1307 matching lines @@
     var v = list[i];
     if ((v is ObservableMap) && _isServiceMap(v)) {
       list[i] = owner.getFromMap(v);
     } else if (v is ObservableList) {
       _upgradeObservableList(v, owner);
     } else if (v is ObservableMap) {
       _upgradeObservableMap(v, owner);
     }
   }
 }