No longer store the compilation-context in WorkItem.

pkg/compiler/lib/src/common/work.dart

 // Copyright (c) 2012, 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.
 
 library dart2js.common.work;
 
 import '../common.dart';
 import '../compiler.dart' show Compiler;
 import '../elements/elements.dart' show AstElement;
 import '../enqueue.dart' show Enqueuer;
 import '../universe/world_impact.dart' show WorldImpact;
 
-/**
- * Contains backend-specific data that is used throughout the compilation of
- * one work item.
- */
-class ItemCompilationContext {}
-
 abstract class WorkItem {
-  final ItemCompilationContext compilationContext;
-  /**
-   * Documentation wanted -- johnniwinther
-   *
-   * Invariant: [element] must be a declaration element.
-   */
+  /// Element on which the work will be done.
   final AstElement element;
 
-  WorkItem(this.element, this.compilationContext) {
+  WorkItem(this.element) {
     assert(invariant(element, element.isDeclaration));
   }
 
   WorldImpact run(Compiler compiler, Enqueuer world);
 }