Trace static tear-off closures.

sdk/lib/_internal/compiler/implementation/inferrer/type_graph_inferrer.dart

Index: sdk/lib/_internal/compiler/implementation/inferrer/type_graph_inferrer.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/inferrer/type_graph_inferrer.dart	(revision 31270)
+++ sdk/lib/_internal/compiler/implementation/inferrer/type_graph_inferrer.dart	(working copy)
@@ -59,9 +59,8 @@
   final Map<Node, TypeInformation> allocatedLists =
       new Map<Node, TypeInformation>();
 
-  /// [ClosureTypeInformation] for allocated closures.
-  final Map<Node, TypeInformation> allocatedClosures =
-      new Map<Node, TypeInformation>();
+  /// Closures found during the analysis.
+  final Set<TypeInformation> allocatedClosures = new Set<TypeInformation>();
 
   /// Cache of [ConcreteTypeInformation].
   final Map<TypeMask, TypeInformation> concreteTypes =
@@ -307,8 +306,9 @@
   }
 
   TypeInformation allocateClosure(Node node, Element element) {
-    return allocatedClosures[node] =
-        new ClosureTypeInformation(node, element);
+    TypeInformation result = new ClosureTypeInformation(node, element);
+    allocatedClosures.add(result);
+    return result;
   }
 
   TypeInformation allocateMap(TypeInformation keyType,
@@ -486,8 +486,10 @@
       workQueue.add(info.elementType);
     });
 
-    types.allocatedClosures.values.forEach((ClosureTypeInformation info) {
-      ClosureTracerVisitor tracer = new ClosureTracerVisitor(info, this);
+    types.allocatedClosures.forEach((info) {
+      ClosureTracerVisitor tracer = info is ClosureTypeInformation
+          ? new ClosureTracerVisitor(info.element, info, this)
+          : new StaticTearOffClosureTracerVisitor(info.element, info, this);
       tracer.run();
       if (!tracer.continueAnalyzing) return;
       FunctionElement element = info.element;
@@ -626,7 +628,7 @@
   void buildWorkQueue() {
     workQueue.addAll(types.typeInformations.values);
     workQueue.addAll(types.allocatedTypes);
-    workQueue.addAll(types.allocatedClosures.values);
+    workQueue.addAll(types.allocatedClosures);
     workQueue.addAll(allocatedCalls);
   }
 
@@ -659,11 +661,14 @@
         info.closurizedCount--;
       } else {
         info.closurizedCount++;
+        if (Elements.isStaticOrTopLevel(callee)) {
+          types.allocatedClosures.add(info);
+        }
         FunctionElement function = callee.implementation;
         FunctionSignature signature = function.computeSignature(compiler);
         signature.forEachParameter((Element parameter) {
           ElementTypeInformation info = types.getInferredTypeOf(parameter);
-          info.giveUp(this);
+          info.giveUp(this, clearAssignments: false);
           if (addToQueue) workQueue.addAll(info.users);
         });
       }