Use closure tracer to identify closures that are not passed to Function.apply

sdk/lib/_internal/compiler/implementation/inferrer/map_tracer.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 type_graph_inferrer;
 
 Set<String> okMapSelectorsSet = new Set.from(
     const <String>[
       // From Object.
       "==",
       "hashCode",
       "toString",
       "noSuchMethod",
       "runtimeType",
       // From Map
       "[]",
       "isEmpty",
       "isNotEmpty",
       "keys",
       "length",
       "values",
       "clear",
       "containsKey",
       "containsValue",
       "forEach",
       "remove"]);
 
-class MapTracerVisitor extends TracerVisitor {
+class MapTracerVisitor extends TracerVisitor<MapTypeInformation> {
   // These lists are used to keep track of newly discovered assignments to
   // the map. Note that elements at corresponding indices are expected to
   // belong to the same assignment operation.
   List<TypeInformation> keyAssignments = <TypeInformation>[];
   List<TypeInformation> valueAssignments = <TypeInformation>[];
   // This list is used to keep track of assignments of entire maps to
   // this map.
   List<MapTypeInformation> mapAssignments = <MapTypeInformation>[];
 
   MapTracerVisitor(tracedType, inferrer) : super(tracedType, inferrer);
@@ skipping 75 matching lines @@
           return;
         }
       }
     } else if (selector.isCall() &&
                !info.targets.every((element) => element.isFunction())) {
       bailout('Passed to a closure');
       return;
     }
   }
 }