Fixed missing method referenced when MallocHooks is unsupported.

runtime/observatory/lib/src/service/object.dart

Index: runtime/observatory/lib/src/service/object.dart
diff --git a/runtime/observatory/lib/src/service/object.dart b/runtime/observatory/lib/src/service/object.dart
index cbaae26eff6135bc776a8fa7e941aeac4a4af569..656bf20dc713b20b8808c7ac05670360498aa9e4 100644
--- a/runtime/observatory/lib/src/service/object.dart
+++ b/runtime/observatory/lib/src/service/object.dart
@@ -776,29 +776,28 @@ abstract class VM extends ServiceObjectOwner implements M.VM {
       return this;
     }
 
-    assert(type == 'Isolate');
     String id = map['id'];
-    if (!id.startsWith(_isolateIdPrefix)) {
-      // Currently the VM only supports upgrading Isolate ServiceObjects.
-      throw new UnimplementedError();
-    }
-
-    // Check cache.
-    var isolate = _isolateCache[id];
-    if (isolate == null) {
-      // Add new isolate to the cache.
-      isolate = new ServiceObject._fromMap(this, map);
-      _isolateCache[id] = isolate;
-      _buildIsolateList();
-
-      // Eagerly load the isolate.
-      isolate.load().catchError((e, stack) {
-        Logger.root.info('Eagerly loading an isolate failed: $e\n$stack');
-      });
-    } else {
-      isolate.update(map);
+    if ((id != null) && id.startsWith(_isolateIdPrefix)) {
+      // Check cache.
+      var isolate = _isolateCache[id];
+      if (isolate == null) {
+        // Add new isolate to the cache.
+        isolate = new ServiceObject._fromMap(this, map);
+        _isolateCache[id] = isolate;
+        _buildIsolateList();
+
+        // Eagerly load the isolate.
+        isolate.load().catchError((e, stack) {
+          Logger.root.info('Eagerly loading an isolate failed: $e\n$stack');
+        });
+      } else {
+        isolate.update(map);
+      }
+      return isolate;
     }
-    return isolate;
+
+    // Build the object from the map directly.
+    return new ServiceObject._fromMap(this, map);
   }
 
   // Note that this function does not reload the isolate if it found
@@ -3009,7 +3008,7 @@ class ServiceFunction extends HeapObject implements M.Function {
   ServiceFunction._empty(ServiceObject owner) : super._empty(owner);
 
   void _update(Map map, bool mapIsRef) {
-    _upgradeCollection(map, isolate);
+    _upgradeCollection(map, owner);
     super._update(map, mapIsRef);
 
     name = map['name'];