Deal with Javascript integer limitations in heap snapshot processing to handle 64-bit target VMs.

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;
 
 /// Helper function for canceling a Future<StreamSubscription>.
 Future cancelFutureSubscription(
     Future<StreamSubscription> subscriptionFuture) async {
   if (subscriptionFuture != null) {
@@ skipping 918 matching lines @@
   final Isolate isolate;
 
   HeapSnapshot(this.isolate, chunks, nodeCount) :
       graph = new ObjectGraph(chunks, nodeCount),
       timeStamp = new DateTime.now();
 
   List<Future<ServiceObject>> getMostRetained({int classId, int limit}) {
     var result = [];
     for (ObjectVertex v in graph.getMostRetained(classId: classId,
                                                  limit: limit)) {
-      result.add(isolate.getObjectByAddress(v.address.toRadixString(16))
+      result.add(isolate.getObjectByAddress(v.address)
                         .then((ServiceObject obj) {
         if (obj is Instance) {
           // TODO(rmacnak): size/retainedSize are properties of all heap
           // objects, not just Instances.
           obj.retainedSize = v.retainedSize;
         }
         return obj;
       }));
     }
     return result;
@@ skipping 2606 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);
     }
   }
 }