Omnibus Observatory UI fixes:

runtime/observatory/lib/src/elements/retaining_path.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:html';
 import 'dart:async';
 import 'package:observatory/models.dart' as M;
 import 'package:observatory/src/elements/curly_block.dart';
 import 'package:observatory/src/elements/instance_ref.dart';
 import 'package:observatory/src/elements/helpers/any_ref.dart';
 import 'package:observatory/src/elements/helpers/rendering_scheduler.dart';
 import 'package:observatory/src/elements/helpers/tag.dart';
 
 class RetainingPathElement extends HtmlElement implements Renderable {
   static const tag = const Tag<RetainingPathElement>('retaining-path',
       dependencies: const [CurlyBlockElement.tag, InstanceRefElement.tag]);
 
   RenderingScheduler<RetainingPathElement> _r;
 
   Stream<RenderedEvent<RetainingPathElement>> get onRendered => _r.onRendered;
 
   M.IsolateRef _isolate;
   M.ObjectRef _object;
   M.RetainingPathRepository _retainingPaths;
-  M.InstanceRepository _instances;
+  M.ObjectRepository _objects;
   M.RetainingPath _path;
   bool _expanded = false;
 
   M.IsolateRef get isolate => _isolate;
   M.ObjectRef get object => _object;
 
   factory RetainingPathElement(M.IsolateRef isolate, M.ObjectRef object,
-      M.RetainingPathRepository retainingPaths, M.InstanceRepository instances,
+      M.RetainingPathRepository retainingPaths, M.ObjectRepository objects,
       {RenderingQueue queue}) {
     assert(isolate != null);
     assert(object != null);
     assert(retainingPaths != null);
-    assert(instances != null);
+    assert(objects != null);
     RetainingPathElement e = document.createElement(tag.name);
     e._r = new RenderingScheduler(e, queue: queue);
     e._isolate = isolate;
     e._object = object;
     e._retainingPaths = retainingPaths;
-    e._instances = instances;
+    e._objects = objects;
     return e;
   }
 
   RetainingPathElement.created() : super.created();
 
   @override
   void attached() {
     super.attached();
     _r.enable();
   }
@@ skipping 43 matching lines @@
 
   Element _createItem(M.RetainingPathItem item, bool first) {
     final content = <Element>[];
 
     if (first) {
       // No prefix.
     } else if (item.parentField != null) {
       content.add(new SpanElement()
         ..children = [
           new SpanElement()..text = 'retained by ',
-          anyRef(_isolate, item.parentField, _instances, queue: _r.queue),
+          anyRef(_isolate, item.parentField, _objects, queue: _r.queue),
           new SpanElement()..text = ' of ',
         ]);
     } else if (item.parentListIndex != null) {
       content.add(new SpanElement()
         ..text = 'retained by [ ${item.parentListIndex} ] of ');
     } else if (item.parentWordOffset != null) {
       content.add(new SpanElement()
         ..text = 'retained by offset ${item.parentWordOffset} of ');
     } else {
       content.add(new SpanElement()..text = 'retained by ');
     }
 
-    content.add(anyRef(_isolate, item.source, _instances, queue: _r.queue));
+    content.add(anyRef(_isolate, item.source, _objects, queue: _r.queue));
 
     return new DivElement()
       ..classes = ['indent']
       ..children = content;
   }
 
   Element _createGCRootItem() {
     return new DivElement()
       ..classes = ['indent']
       ..text = 'retained by a GC root';
   }
 }