Hide internal classes from Memory Profile

runtime/observatory/lib/src/elements/memory/allocations.dart

 // Copyright (c) 2017, 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.
 
 /// This Element is part of MemoryDashboardElement.
 ///
 /// The Element is stripped down version of AllocationProfileElement where
 /// concepts like old and new space has been hidden away.
 ///
 /// For each class in the system it is shown the Total number of instances
@@ skipping 91 matching lines @@
       children = [
         new DivElement()
           ..classes = ['content-centered-big']
           ..children = [new HeadingElement.h2()..text = 'Loading...']
       ];
     } else {
       children = [
         new VirtualCollectionElement(
             _createCollectionLine, _updateCollectionLine,
             createHeader: _createCollectionHeader,
-            items: _profile.members.toList()..sort(_createSorter()),
+            items: _profile.members
+                .where((member) =>
+                    member.newSpace.accumulated.instances != 0 ||
+                    member.newSpace.current.instances != 0 ||
+                    member.oldSpace.accumulated.instances != 0 ||
+                    member.oldSpace.current.instances != 0)
+                .toList()
+                  ..sort(_createSorter()),
             queue: _r.queue)
       ];
     }
   }
 
   _createSorter() {
     var getter;
     switch (_sortingField) {
       case _SortingField.accumulatedSize:
         getter = _getAccumulatedSize;
@@ skipping 103 matching lines @@
       _sortingField = field;
     }
     _r.dirty();
   }
 
   void _updateCollectionLine(Element e, M.ClassHeapStats item, index) {
     e.children[0].text = Utils.formatSize(_getAccumulatedSize(item));
     e.children[1].text = '${_getAccumulatedInstances(item)}';
     e.children[2].text = Utils.formatSize(_getCurrentSize(item));
     e.children[3].text = '${_getCurrentInstances(item)}';
+    if (item.clazz == null) {
+      e.children[4] = new SpanElement()
+        ..text = item.displayName
+        ..classes = ['name'];
+      return;
+    }
     e.children[4] = new ClassRefElement(_isolate, item.clazz, queue: _r.queue)
       ..classes = ['name'];
     Element.clickEvent.forTarget(e.children[4], useCapture: true).listen((e) {
       if (_editor.isAvailable) {
         e.preventDefault();
         _editor.openClass(isolate, item.clazz);
       }
     });
   }
 
   Future _refresh({bool gc: false, bool reset: false}) async {
     _profile = null;
     _r.dirty();
-    _profile = await _repository.get(_isolate, gc: gc, reset: reset);
+    _profile =
+        await _repository.get(_isolate, gc: gc, reset: reset, combine: true);
     _r.dirty();
   }
 
   static int _getAccumulatedSize(M.ClassHeapStats s) =>
       s.newSpace.accumulated.bytes + s.oldSpace.accumulated.bytes;
   static int _getAccumulatedInstances(M.ClassHeapStats s) =>
       s.newSpace.accumulated.instances + s.oldSpace.accumulated.instances;
   static int _getCurrentSize(M.ClassHeapStats s) =>
       s.newSpace.current.bytes + s.oldSpace.current.bytes;
   static int _getCurrentInstances(M.ClassHeapStats s) =>
       s.newSpace.current.instances + s.oldSpace.current.instances;
 }