Add RPC and UI for reachable size of an object / all instances of a class.

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

 // 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.
 
 library class_view_element;
 
 import 'dart:async';
 import 'observatory_element.dart';
 import 'package:observatory/cpu_profile.dart';
 import 'package:observatory/elements.dart';
 import 'package:observatory/service.dart';
 import 'package:polymer/polymer.dart';
 
 @CustomTag('class-view')
 class ClassViewElement extends ObservatoryElement {
   @published Class cls;
   @observable ServiceMap instances;
+  @observable int reachableBytes;
   @observable int retainedBytes;
   @observable ObservableList mostRetained;
   SampleBufferControlElement sampleBufferControlElement;
   StackTraceTreeConfigElement stackTraceTreeConfigElement;
   CpuProfileTreeElement cpuProfileTreeElement;
 
   ClassViewElement.created() : super.created();
 
   Future<ServiceObject> evaluate(String expression) {
     return cls.evaluate(expression);
   }
 
   Future<ServiceObject> reachable(var limit) {
     return cls.isolate.getInstances(cls, limit).then((ServiceMap obj) {
       instances = obj;
     });
   }
 
   Future<ServiceObject> retainedToplist(var limit) {
     return cls.isolate.fetchHeapSnapshot().last
       .then((HeapSnapshot snapshot) =>
           Future.wait(snapshot.getMostRetained(classId: cls.vmCid,
                                                limit: 10)))
       .then((List<ServiceObject> most) {
         mostRetained = new ObservableList.from(most);
       });
   }
 
   // TODO(koda): Add no-arg "calculate-link" instead of reusing "eval-link".
+  Future<ServiceObject> reachableSize(var dummy) {
+    return cls.isolate.getReachableSize(cls).then((Instance obj) {
+      reachableBytes = int.parse(obj.valueAsString);
+    });
+  }
+
   Future<ServiceObject> retainedSize(var dummy) {
     return cls.isolate.getRetainedSize(cls).then((Instance obj) {
       retainedBytes = int.parse(obj.valueAsString);
     });
   }
 
   void attached() {
     super.attached();
     sampleBufferControlElement =
         shadowRoot.querySelector('#sampleBufferControl');
@@ skipping 52 matching lines @@
     return sampleBufferControlElement.reload(cls.isolate);
   }
 
   Future toggleAllocationTrace() {
     if (cls == null) {
       return new Future(refresh);
     }
     return cls.setTraceAllocations(!cls.traceAllocations).whenComplete(refresh);
   }
 }