Move ResolutionWorkItem to resolution_strategy.dart

pkg/compiler/lib/src/enqueue.dart

Index: pkg/compiler/lib/src/enqueue.dart
diff --git a/pkg/compiler/lib/src/enqueue.dart b/pkg/compiler/lib/src/enqueue.dart
index d803bc5143bbed78fb4ff766005561735f925f30..18740a1f71d9d636104cf52a6ace577c260c574f 100644
--- a/pkg/compiler/lib/src/enqueue.dart
+++ b/pkg/compiler/lib/src/enqueue.dart
@@ -14,7 +14,7 @@ import 'common_elements.dart' show ElementEnvironment;
 import 'constants/values.dart';
 import 'compiler.dart' show Compiler;
 import 'options.dart';
-import 'elements/elements.dart' show AnalyzableElement, MemberElement;
+import 'elements/elements.dart' show MemberElement;
 import 'elements/entities.dart';
 import 'elements/resolution_types.dart' show ResolutionTypedefType;
 import 'elements/types.dart';
@@ -609,21 +609,3 @@ class DeferredAction {
 abstract class WorkItemBuilder {
   WorkItem createWorkItem(MemberEntity entity);
 }
-
-/// Builder that creates work item necessary for the resolution of a
-/// [MemberElement].
-class ResolutionWorkItemBuilder extends WorkItemBuilder {
-  final Resolution _resolution;
-
-  ResolutionWorkItemBuilder(this._resolution);
-
-  @override
-  WorkItem createWorkItem(MemberElement element) {
-    assert(invariant(element, element.isDeclaration));
-    if (element.isMalformed) return null;
-
-    assert(invariant(element, element is AnalyzableElement,
-        message: 'Element $element is not analyzable.'));
-    return _resolution.createWorkItem(element);
-  }
-}