Change Enqueuer to use Entity instead of Element.

pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart

Index: pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart
diff --git a/pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart b/pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart
index 67f2aa0db0274aa21e24efaaaa975948233f9e6a..16053883cf448680a3e2b0ed37b29818babd9f87 100644
--- a/pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart
+++ b/pkg/compiler/lib/src/inferrer/type_graph_inferrer.dart
@@ -1247,11 +1247,8 @@ class TypeGraphInferrerEngine
   Iterable<ResolvedAst> sortResolvedAsts() {
     int max = 0;
     Map<int, Setlet<ResolvedAst>> methodSizes = <int, Setlet<ResolvedAst>>{};
-    compiler.enqueuer.resolution.processedElements
+    compiler.enqueuer.resolution.processedEntities
         .forEach((AstElement element) {
-      // TODO(ngeoffray): Not sure why the resolver would put a null
-      // mapping.
-      if (!compiler.enqueuer.resolution.hasBeenProcessed(element)) return;
       ResolvedAst resolvedAst = element.resolvedAst;
       element = element.implementation;
       if (element.impliesType) return;