Teach the Observatory about Contexts. Factor out object graph information from the instance view.

runtime/bin/vmservice/observatory/lib/src/elements/instance_view.dart

Index: runtime/bin/vmservice/observatory/lib/src/elements/instance_view.dart
diff --git a/runtime/bin/vmservice/observatory/lib/src/elements/instance_view.dart b/runtime/bin/vmservice/observatory/lib/src/elements/instance_view.dart
index ae7fca9f3e0e34182187e388f31322b97c70022c..556a279a752927bbf9a1b1ccbb8628ffedf689a2 100644
--- a/runtime/bin/vmservice/observatory/lib/src/elements/instance_view.dart
+++ b/runtime/bin/vmservice/observatory/lib/src/elements/instance_view.dart
@@ -12,9 +12,6 @@ import 'package:polymer/polymer.dart';
 @CustomTag('instance-view')
 class InstanceViewElement extends ObservatoryElement {
   @published Instance instance;
-  @published ServiceMap path;
-  @published ServiceMap inboundReferences;
-  @observable int retainedBytes = null;
 
   InstanceViewElement.created() : super.created();
 
@@ -23,29 +20,7 @@ class InstanceViewElement extends ObservatoryElement {
         instance.id + "/eval?expr=${Uri.encodeComponent(text)}");
   }
 
-  // TODO(koda): Add no-arg "calculate-link" instead of reusing "eval-link".
-  Future<ServiceObject> retainedSize(var dummy) {
-    return instance.isolate.get(instance.id + "/retained")
-        .then((ServiceMap obj) {
-          retainedBytes = int.parse(obj['valueAsString']);
-        });
-  }
-
-  Future<ServiceObject> retainingPath(var arg) {
-    return instance.isolate.get(instance.id + "/retaining_path?limit=$arg")
-        .then((ServiceObject obj) {
-          path = obj;
-        });
-  }
-
-  Future<ServiceObject> fetchInboundReferences(var arg) {
-    return instance.isolate.get(instance.id + "/inbound_references?limit=$arg")
-        .then((ServiceObject obj) {
-           inboundReferences = obj;
-        });
-  }
-
-  void refresh(var done) {
-    instance.reload().whenComplete(done);
+  void refresh(Function onDone) {
+    instance.reload().whenComplete(onDone);
   }
 }